Individual Short-chain Fatty Acids Research Articles

Isobutyric acid enhances the anti-tumour effect of anti-PD-1 antibody

The low response rate of immune checkpoint inhibitors (ICIs) is a challenge. The efficacy of ICIs is influenced by the tumour microenvironment, which is controlled by the gut microbiota. In particular, intestinal bacteria and their metabolites, such as short chain fatty acids (SCFAs), are important regulators of cancer immunity; however, our knowledge on the effects of individual SCFAs remains limited. Here, we show that isobutyric acid has the strongest effect among SCFAs on both immune activity and tumour growth. In vitro, cancer cell numbers were suppressed by approximately 75% in humans and mice compared with those in controls. Oral administration of isobutyric acid to carcinoma-bearing mice enhanced the effect of anti-PD-1 immunotherapy, reducing tumour volume by approximately 80% and 60% compared with those in the control group and anti-PD-1 antibody alone group, respectively. Taken together, these findings may support the development of novel cancer therapies that can improve the response rate to ICIs.

Effect of Short-Chain Fatty Acids on Inflammatory and Metabolic Function in an Obese Skeletal Muscle Cell Culture Model.

The fermentation of non-digestible carbohydrates produces short-chain fatty acids (SCFAs), which have been shown to impact both skeletal muscle metabolic and inflammatory function; however, their effects within the obese skeletal muscle microenvironment are unknown. In this study, we developed a skeletal muscle in vitro model to mimic the critical features of the obese skeletal muscle microenvironment using L6 myotubes co-treated with 10 ng/mL lipopolysaccharide (LPS) and 500 µM palmitic acid (PA) for 24 h ± individual SCFAs, namely acetate, propionate and butyrate at 0.5 mM and 2.5 mM. At the lower SCFA concentration (0.5 mM), all three SCFA reduced the secreted protein level of RANTES, and only butyrate reduced IL-6 protein secretion and the intracellular protein levels of activated (i.e., ratio of phosphorylated-total) NFκB p65 and STAT3 (p < 0.05). Conversely, at the higher SCFA concentration (2.5 mM), individual SCFAs exerted different effects on inflammatory mediator secretion. Specifically, butyrate reduced IL-6, MCP-1 and RANTES secretion, propionate reduced IL-6 and RANTES, and acetate only reduced RANTES secretion (p < 0.05). All three SCFAs reduced intracellular protein levels of activated NFκB p65 and STAT3 (p < 0.05). Importantly, only the 2.5 mM SCFA concentration resulted in all three SCFAs increasing insulin-stimulated glucose uptake compared to control L6 myotube cultures (p < 0.05). Therefore, SCFAs exert differential effects on inflammatory mediator secretion in a cell culture model, recapitulating the obese skeletal muscle microenvironment; however, all three SCFAs exerted a beneficial metabolic effect only at a higher concentration via increasing insulin-stimulated glucose uptake, collectively exerting differing degrees of a beneficial effect on obesity-associated skeletal muscle dysfunction.

Features of the metabolic activity of the intestinal microbiota in children with obesity

Purpose: to evaluate the quantitative and qualitative features of the metabolic activity of the intestinal microbiota in patients with obesity. Materials and methods: a comprehensive clinical, laboratory and instrumental examination of 60 children aged 12-16 years was carried out. The main group (n=30) - patients with exogenous constitutional obesity, the comparison group (n=30) - adolescents with normal body weight. The metabolic activity of the intestinal microbiota was assessed by gas-liquid chromatography of a fecal sample with the determination of the relative and absolute values of short-chain fatty acids (SCFAs). Results: All patients with obesity showed a decrease in the concentration of SCFA compared with the comparison group, which indicated a decrease in the metabolic activity of the obligate lactic acid flora and the predominance of the fraction of non-proteolytic anaerobic microorganisms. When assessing the relationship between the lipid spectrum and individual SCFAs and their indices, numerous positive relationships of moderate strength were obtained, which indirectly may indicate the progression of the imbalance of aerobes and anaerobes of the intestinal microbiome with an increase in the degree of metabolic disorders in obese patients. Conclusion: The identified qualitative and quantitative disorders of the intestinal microbiota in obese children are associated with the development of insulin resistance and are a reflection of metabolic endotoxinemia associated with the maintenance of chronic sluggish inflammation in overweight children.

Replacing the forage portion of the ration with triticale hay improves the performance of Holstein dairy cows

The aim of the present study was to assess the effect of replacing the forage portion (alfalfa, corn silage, and barley straw) in the diet of lactating Holstein cows with triticale hay (TH, × Triticosecale L.) on DMI, digestibility, ruminal fermentation variables, estimated microbial-N synthesis (EMNS), and milk production and composition. Eight Holstein cows were used in a replicated Latin square design (two 4 × 4 squares) with four 28-d periods and 4 treatments, including a TH-free diet (control), and diets replacing 33%, 66%, and 100% of the forage portion with TH. Cows were fed ad libitum with 10% carryover during the experimental periods. Intakes and in vivo digestibilities of dry matter, organic matter, crude protein, and ash-free neutral detergent fiber, rumen pH, ammonia-N, total and individual short-chain fatty acids, protozoa, and bacteria populations were evaluated using specific methods. Moreover, in vitro total gas and methane release and in vivo urinary purine derivatives, EMNS, milk production, and composition were measured. The results showed that TH diets lowered DMI, compared with the control. Apparent digestibilities of DM, OM, CP, and NDF increased with dietary TH inclusion. The addition of TH instead of the diet forage portion increased in vivo rumen pH; acetic, propionic, valeric, and isovaleric acids concentrations; cellulolytic bacteria number; and in vitro gas production. In vivo rumen ammonia-N, short-chain fatty acids, butyric acid, in vivo and in vitro total protozoa and Entodiniinae numbers, and in vitro methane production decreased with increasing dietary levels of TH instead of the forage portion. The dietary addition of TH did not affect milk yield, protein, and lactose, but increased fat-corrected milk, milk fat, fat-corrected milk:DMI ratio, and milk yield:DMI ratio. Milk urea N decreased, but urinary purine derivatives excretion and EMNS increased with increasing levels of TH in the diet. For variables with significant changes, except for isovaleric acid, there was a linear response of animals to increasing levels of TH in the diet. Results suggest that TH, which is grown with less water compared with alfalfa, corn forage, and straw, is a potential alternative to those forages by increasing milk production efficiency, milk fat, and decreasing methane emission.

Effects of corn silage and grain expressing α-amylase on ruminal nutrient digestibility, microbial protein synthesis, and enteric methane emissions in lactating cows

Increasing ruminal starch digestibility has the potential to improve microbial protein synthesis (MPS), milk production, and feed efficiency. Enogen corn (Syngenta Seeds LLC) expresses high α-amylase activity, and we evaluated effects of Enogen corn silage (CS) and grain (CG) on ruminal starch digestibility, MPS, and milk production in lactating dairy cows. Fifteen Holstein cows (6 ruminally cannulated and 9 noncannulated; average ± standard deviation at the beginning of the trial: 170 ± 40 d in milk; milk yield, 37.2 ± 7.73 kg/d; body weight, 714 ± 37 kg) were used in a replicated 3 × 3 Latin square design (28 d per period) with 3 treatments: a diet containing isoline CS and CG (control, CON); a diet with Enogen CS and isoline CG (ECS); and a diet with Enogen CS and CG (ECSCG). Dry matter (DM; 30%), starch (35% of DM), and particle size distribution of the isoline and Enogen CS were similar. However, the mean particle size of Enogen CG was larger (1.05 vs. 0.65 mm) than that of the isoline CG. Cannulated cows were used for digestibility and nutrient flow measurements, noncannulated cows were used for enteric CH4 measurements, and all cows were used for production evaluation. Dry matter intake (DMI) and milk yield were greater for ECS and ECSCG compared with CON (26.7 and 26.6 vs. 25.1 kg/d and 36.5 and 34.1 vs. 33.1 kg/d, respectively) without a difference between ECS and ECSCG. Milk protein yield was greater (1.27 vs. 1.14 and 1.17 kg/d) for ECS compared with CON and ECSCG. Milk fat content was greater (3.79 vs. 3.32%) for ECSCG compared with ECS. Milk fat yield and energy-corrected milk did not differ among treatments. Ruminal digestibilities of DM, organic matter, starch, and neutral detergent fiber were not different among treatments. However, ruminal digestibility of nonammonia, nonmicrobial N was greater (85 vs. 75%) for ECS compared with ECSCG. Total-tract apparent starch digestibility was lower (97.6 and 97.1 vs. 98.3%) for ECS and ECSCG compared with CON, respectively, and tended to be lower (97.1 vs. 98.3%) for ECSCG compared with ECS. Ruminal outflows of bacterial OM and nonammonia N tended to be greater for ECS than for ECSCG. Efficiency of MPS tended to be greater (34.1 vs. 30.6 g of N/kg of organic matter truly digested) for ECS versus ECSCG. Ruminal pH and total and individual short-chain fatty acid concentrations did not differ among treatments. Concentration of ruminal NH3 for ECS and ECSCG was lower (10.4 and 12.4 vs. 13.4 mmol/L, respectively) compared with CON. Methane per unit of DMI decreased for ECS and ECSCG compared with CON (11.4 and 12.2 vs. 13.5 g/kg of DMI, respectively) without a difference between ECS and ECSCG. In conclusion, ECS and ECSCG did not increase ruminal or total-tract starch digestibility. However, the positive effects of ECS and ECSCG on milk protein yield, milk yield, and CH4 per unit of DMI may show potential benefits of feeding Enogen corn. Effects of ECSCG were not apparent when compared with ECS, partly due to larger particle size of Enogen CG compared with its isoline counterpart.

Probiotic Yoghurt Enriched with Mango Peel Powder: Biotransformation of Phenolics and Modulation of Metabolomic Outputs after In Vitro Digestion and Colonic Fermentation.

This study investigated the health-promoting effects and prebiotic functions of mango peel powder (MPP) both as a plain individual ingredient and when incorporated in yoghurt during simulated digestion and fermentation. The treatments included plain MPP, plain yoghurt (YA), yoghurt fortified with MPP (YB), and yoghurt fortified with MPP and lactic acid bacteria (YC), along with a blank (BL). The identification of polyphenols in the extracts of insoluble digesta and phenolic metabolites after the in vitro colonic fermentation were performed employing LC-ESI-QTOF-MS2. These extracts were also subjected to pH, microbial count, production of SCFA, and 16S rRNA analyses. The characterisation of phenolic profiles identified 62 phenolic compounds. Among these compounds, phenolic acids were the major compounds that underwent biotransformation via catabolic pathways such as ring fission, decarboxylation, and dehydroxylation. Changes in pH indicated that YC and MPP reduced the media pH from 6.27 and 6.33 to 4.50 and 4.53, respectively. This decline in pH was associated with significant increases in the LAB counts of these samples. The Bifidobacteria counts were 8.11 ± 0.89 and 8.02 ± 1.01 log CFU/g in YC and MPP, respectively, after 72 h of colonic fermentation. Results also showed that the presence of MPP imparted significant variations in the contents and profiles of individual short chain fatty acids (SCFA) with more predominant production of most SCFA in the MPP and YC treatments. The 16s rRNA sequencing data indicated a highly distinctive microbial population associated with YC in terms of relative abundance. These findings suggested MPP as a promising ingredient for utilisation in functional food formulations aiming to enhance gut health.

Abstract 4228: Replacing red and processed meat with legumes modulates gut microbiome and microbiota-related metabolites linked to gut health and cancer prevention in healthy working-aged men

Abstract Background and Aim: Changing dietary habits have great potential for colorectal cancer (CRC) prevention. Regardless of the accumulated evidence on the relationship between dietary protein sources and CRC, the explaining mechanisms remain not well established. Diet-delivered microbial metabolites such as secondary bile acids (BA), N-nitroso compounds (NOC), trimethylamine N-oxide (TMAO), short-chain fatty acid (SCFA), and branched-chain fatty acids (BCFA) have been suggested to mediate the relationship. The aim of this study was to examine the effects of partial replacement of red and processed meat (RPM), associated with higher CRC risk, with legumes on the fecal microbiota composition and metabolite profiles in healthy men. Methods: The study was a partly controlled 6-wk parallel design randomized clinical trial (n=102, age 37 y (range 21 - 61 y), BMI 25.5 ± 3.3 kg/m2) with two groups following either a diet supplemented with RPM (meat group) or a diet supplemented with legumes and RPM (legume group). The amount of RPM (200 g/wk) in the legume group was based on the maximum amount recommended by the EAT-Lancet Commission whereas the amount in the meat group (760 g/wk) corresponded the average intake of Finnish men. Fecal SCFAs (µg/ml) and BCFAs (µg/ml) were analyzed with GS-MS, BAs (arbitrary, analyte/standard ratios) with UHPLC-MS/MS, and NOCs (pmol/mg) with selective de-nitrosation and chemiluminescence-based detection. Urine TMAO was quantified by NMR and fecal microbiota composition was analyzed using 16S rRNA amplicon sequencing techniques. Dietary intakes were analyzed with 4-day food records. Results: At the baseline, no significant differences (p &amp;gt; 0.05) were reported in age, BMI, dietary intake of total fiber (g/d), protein (E%), fat (E%), or in the fecal metabolites. The legume group had more pronounced effects on the gut microbiota community level, indicating ecosystem level differences. Total NOCs (p &amp;lt; 0.0001) and heme-originated NOCs (FeNO; p &amp;lt; 0.0001) were smaller in the legume group than in the meat group. Significant differences between the groups were observed in intake of total fiber (p &amp;lt; 0.001), cholesterol (mg/d, p &amp;lt; 0.001), saturated (p &amp;lt; 0.005), and polyunsaturated fat (p &amp;lt; 0.001). Although not significant (p &amp;gt; 0.05), total, secondary and unconjugated BAs, and total BCFA were higher in the meat group, whereas primary and conjugated BAs and total SCFAs were higher in the legume group. The concentration of total SCFA and individual SCFA decreased in both groups during the intervention period. Overall, a large sample-to-sample variation was observed. Conclusions: The results indicate that partial replacement of RPM with legume products can potentially change microbiota activity and gut metabolites, suggesting a protective gut metabolic profile against colorectal cancer. Citation Format: Tuulia Pietilä, Isabell Schreck, Tiina Pellinen, Johanna Vauhkonen, Essi Päivärinta, Mikko Neuvonen, Mikko Niemi, Anne Salonen, Anne-Maria Pajari. Replacing red and processed meat with legumes modulates gut microbiome and microbiota-related metabolites linked to gut health and cancer prevention in healthy working-aged men. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4228.

A50 THE EFFECTS OF SHORT-CHAIN FATTY ACIDS ON EPITHELIAL AND MACROPHAGE RESPONSE TO BACTEROIDES FRAGILIS

Abstract Background Patients with IBD have an altered microbiome and gut microenvironment leading to changes in their Short-Chain Fatty Acid (SCFA) profile. Pathobionts are commensal organisms that become pathogenic under specific conditions, likely related to microenvironmental gut changes. This is especially relevant to children given that early life exposures are critical to microbiome development and impact immune response. Purpose The objectives of our study were to: 1) determine if microbes from IBD patients are more proinflammatory compared to non-IBD microbes; and 2) define how SCFAs affect host-response to potential pathobionts. Method Fructooligosaccharide (FOS) fermentation and SCFA production were assessed by HPLC-RID using whole-intestinal microbe culture collected as mucosal washes from pIBD (n=10) and non-IBD patients (n=8). Individual anaerobic bacteria were isolated from individual patients and screened for proinflammatory response [interleukin (IL)-1ß] using THP-1 macrophages. Caco-2 (epithelial) or THP-1 cells were pre-exposed to individual SCFAs (50 mM acetate or formate; 10 mM succinate; or 1 mM butyrate or propionate), then infected with Bacteroides fragilis, isolated from patients. Microscopy (bacterial staining with HEMA 3), qPCR, ELISA, TransEpithelial Electrical Resistance (TEER), and culturing were used to determine invasion potential, cytokine expression, barrier, and secretion. Result(s) FOS fermentation by microbes from IBD patients led to increased acetate and decreased butyrate production. Microbes from IBD patients were more proinflammatory, with increased IL-1ß secretion and reactive oxygen species generation, compared to those from non-IBD patients. B. fragilis isolated from an IBD patient was found to be a potential pathobiont with increased invasion and cytokine production in both epithelial and macrophage cells. Invasion was further increased when cells were exposed to SCFAs, particularly acetate and butyrate. Furthermore, the strain isolated from the IBD patient was observed (by microscopy) to be more adherent to the epithelial barrier, causing a loss of membrane integrity (TEER). The inflammasome pathway were significantly upregulated in Caco-2 cells infected with IBD-isolated B. fragilis and incubated with acetate or butyrate. Conclusion(s) The altered microbiome in IBD patients leads to an increased acetate and decreased butyrate, which likely affects host response to microbes and promotes inflammation. This changed microenvironment promotes the development of pathobionts, such as the identified B. fragilis strain we isolated from an IBD patient. The observation that acetate and butyrate increased host susceptibility to this strain indicates that understanding diet and SCFA production are instrumental in treating chronic conditions such as IBD. The role of diet as both a treatment and potential cause of inflammation in IBD is becoming more apparent; therefore, it is crucial that we understand the complex role diet has in host-microbe interactions. Please acknowledge all funding agencies by checking the applicable boxes below CIHR, Other Please indicate your source of funding; Mitacs- Weston Foundation Disclosure of Interest None Declared

Short-Chain Fatty Acids in the Microbiota-Gut-Brain Axis: Role in Neurodegenerative Disorders and Viral Infections.

The gut-brain axis (GBA) is the umbrella term to include all bidirectional communication between the brain and gastrointestinal (GI) tract in the mammalian body. Evidence from over two centuries describes a significant role of GI microbiome in health and disease states of the host organism. Short-chain fatty acids (SCFAs), mainly acetate, butyrate, and propionate that are the physiological forms of acetic acid, butyric acid, and propionic acid respectively, are GI bacteria derived metabolites. SCFAs have been reported to influence cellular function in multiple neurodegenerative diseases (NDDs). In addition, the inflammation modulating properties of SCFAs make them suitable therapeutic candidates in neuroinflammatory conditions. This review provides a historical background of the GBA and current knowledge of the GI microbiome and role of individual SCFAs in central nervous system (CNS) disorders. Recently, a few reports have also identified the effects of GI metabolites in the case of viral infections. Among these viruses, the flaviviridae family is associated with neuroinflammation and deterioration of CNS functions. In this context, we additionally introduce SCFA based mechanisms in different viral pathogenesis to understand the former's potential as agents against flaviviral disease.

Effect of replacement of soybean oil by Hermetia illucens fat on performance, digestibility, cecal microbiome, liver transcriptome and liver and plasma lipidomes of broilers

BackgroundIn contrast to protein-rich insect meal, the feed potential of insect fat is generally less explored and knowledge about the suitability of insect fat as a fat source specifically in broiler diets is still limited. In view of this, the present study aimed to comprehensively investigate the effect of partial (50%) and complete replacement of soybean oil with insect fat from Hermetia illucens (HI) larvae in broiler diets on performance, fat digestibility, cecal microbiome, liver transcriptome and liver and plasma lipidomes. Thus, 100 male, 1-day-old Cobb 500 broilers were randomly assigned to three groups and fed three different diets with either 0 (group HI-0, n = 30), 2.5% (group HI-2.5, n = 35) or 5.0% (HI-5.0, n = 35) Hermetia illucens (HI) larvae fat for 35 d.ResultsBody weight gain, final body weight, feed intake, and feed:gain ratio during the whole period and apparent ileal digestibility coefficient for ether extract were not different between groups. Cecal microbial diversity did not differ between groups and taxonomic analysis revealed differences in the abundance of only four low-abundance bacterial taxa among groups; the abundances of phylum Actinobacteriota, class Coriobacteriia, order Coriobacteriales and family Eggerthellaceae were lower in group HI-5.0 compared to group HI-2.5 (P < 0.05). Concentrations of total and individual short-chain fatty acids in the cecal digesta were not different between the three groups. Liver transcriptomics revealed a total of 55 and 25 transcripts to be differentially expressed between groups HI-5.0 vs. HI-0 and groups HI-2.5 vs. HI-0, respectively (P < 0.05). The concentrations of most lipid classes, with the exception of phosphatidylethanolamine, phosphatidylglycerol and lysophosphatidylcholine in the liver and cholesterylester and ceramide in plasma (P < 0.05), and of the sum of all lipid classes were not different between groups.ConclusionsPartial and complete replacement of soybean oil with HI larvae fat in broiler diets had no effect on growth performance and only modest, but no adverse effects on the cecal microbiome and the metabolic health of broilers. This suggests that HI larvae fat can be used as an alternative fat source in broiler diets, thereby, making broiler production more sustainable.

Fermentation Products of Sugar-Beet Fiber by Cecal Bacteria Lower Plasma Cholesterol Concentration in Rats

Plasma cholesterol concentration is reduced by feeding some dietary fibers but the mechanism is not fully understood. We examined whether cecal fermentation products are involved in lowering plasma cholesterol by feeding rats a highly fermentable sugar-beet fiber (SBF) in four separate experiments. These were designed to investigate the effects on plasma cholesterol of oral ingestion of fermentation products on plasma cholesterol, the effects of the products in comparison with that of a short-chain fatty acid (SCFA) mixture, effects of individual SCFA and effects of alteration of energy and nitrogen ratio in the diet by the addition of the SCFA mixture. Cecal contents of rats were cultured with SBF by using a jar fermenter under anaerobic conditions, and the supernatant from the culture medium, containing fermentation products of SBF, was collected and freeze-dried before feeding to rats. Yield of fermentation products as dry weight from the fiber was 80–90%. In rats fed a diet containing fermentation products (80 g/kg diet), plasma cholesterol concentrations were lower than in rats of the fiber-free group 3, 7 and 14 d after feeding the test diet. Major SCFA in the fermentation products were sodium salts of acetic, propionic and butyric acids. Plasma cholesterol concentration in rats fed the diet containing a mixture of equal amounts of the three SCFA salts (66 g/kg diet) as the fermentation products diet was also lower than that in the fiber-free group and was not different from those in rats fed SBF (100 g/kg diet) and the fermentation products. In rats fed an acetate-containing diet but not in rats fed diets without acetate, plasma cholesterol was significantly lower than in the fiber-free group. In conclusion, absorption of SCFA from cecal fermentation products lowers plasma cholesterol. Acetate, and not propionate, may be responsible for lowering plasma cholesterol concentration.

Wet-food diet promotes the recovery from surgery of castration and control of body weight in adult young cats.

Inappropriate dietary management may lead to delayed recovery from castration surgery and significant weight gain in cats after castration. Wet canned food often exhibits more advantageous characteristics than dry food (e.g., higher palatability and digestibility, and lower energy density). This study compared the effects of canned and dry food on surgical recovery and weight management in cats after castration. Eighteen healthy cats (weighed 4.33 ± 1.04 kg and aged 18-months old) were allocated to one of the two dietary treatments (N = 9/group), dry (CON) and canned food (CAN) balanced for sex and initial BW. Cats were fed ad libitum for 7 weeks, including one week before surgery (week 0) and 6 weeks after surgery (week 1-6). Daily dry matter intake (DMI), and weekly body weight (BW) and body condition score (BCS) was obtained. Feces were collected for measuring nutrient digestibility and concentrations of short-chain fatty acids (SCFA) and branched-chain fatty acids (BCFA). Physical pain and wound surface assessment were performed at week 1. Blood was also collected intermittently for measuring biochemical indices and untargeted metabolomics analysis. Results indicated that BW, BCS and daily DMI in CON group increased (P < 0.05) over time after castration, but were maintained relatively stable in CAN group. Cats in CAN group exhibited less pain-related behavior as reflected by lower score of comfort (P < 0.05) and vocalization (P < 0.10), improved wound surface assessment (P < 0.10), lower level of lipase (P < 0.10) and ratio of blood urea nitrogen/serum creatinine (BUN/SC; P < 0.05), and higher level of superoxide dismutase (SOD; P < 0.05) in week 1 than CON cats. Meanwhile, the CAN group had significantly higher concentration of immunoglobulin G (IgG) on days 5 and 7, and higher level of high-density lipoprotein cholesterol (HDL-C; P < 0.10) but lower triglyceride (TG; P < 0.05) than CON group on day 20 and 48. Fecal total and most individual SCFA increased significantly from week 1 to week 6 regardless of diet, but the increase of butyric acid over time only occurred in CON group (P < 0.05). Also, serum metabolomic analysis revealed differential metabolic pathways between the two groups. Overall, compared with the dry food, the canned food tested in our study promoted cat wound recovery by reducing pain and increasing immune and antioxidative capacity after sterilizing surgery, and helped to maintain healthy body condition in cats after castration.

Опыт использования метапребиотических продуктов в питании детей с запорами

Objective. To evaluate the effect of metaprebiotic products on the state of intestinal function in children with neurological pathology. Patients and methods. This study included 32 children with neurological pathology suffering from chronic constipation and gut microbiota dysbiosis: 13 boys and 19 girls aged between 6 months and 6 years (mean age: 4.6 ± 1.6 years). Patients were divided into a study group and a comparison group. The study group received a specialized product with metaprebiotic properties in addition to the standard diet for 14 days. Anthropometric characteristics, product tolerance, including stool frequency and consistency, were evaluated, and the metabolic activity of anaerobic bacteria was analyzed based on the concentrations of short-chain fatty acids (SCFAs) in stool samples by gas-liquid chromatography. Results. In the study group, stool frequency increased from 0.61 ± 0.25 times per day at the beginning of the study to 0.93 ± 0.11 times per day at the end of the study (p &lt; 0.05) against the background of metaprebiotic product application. In the comparison group, stool frequency did not change statistically significantly (0.7 ± 0.19 and 0.85 ± 0.15 times per day at the beginning and end of the study, respectively). Children in the study group showed an increase in the absolute concentrations of C2-C4 SCFAs (p &lt; 0.05). No statistically significant changes were found in both absolute and relative concentrations of individual SCFAs (acetic, propionic, and butyric acids) in any of the groups. Conclusion. The results of this study showed the effectiveness of a specialized food product with metaprebiotic properties based on inulin and oligofructose containing calcium lactate in the correction of intestinal function in children with neurological pathology. Key words: children, constipation, inulin, oligofructose, prebiotics, specialized food products

Essential oil from Arnica montana alters the protein metabolism in lambs fed with high-concentrate diets

The objective of this study was to evaluate the effect of essential oil (EO) from Arnica montana as an additive on nutrient intake and digestibility, nitrogen balance, and rumen fermentation characteristics in feedlot lambs. Five ruminally cannulated Dorper × Santa Inês ram lambs, castrated, with 50.6 ± 1.19 kg of initial BW and 14.6 ± 1.28 month-old were distributed in a 5 × 5 Latin square design. All lambs were fed a basal diet (160.5 ± 3.06 g/kg DM of CP) containing 90 % concentrate and 10 % forage (Coastcross hay) to which the following 5 treatments were applied: 1. 0 mg/kg DM of OE from Arnica montana (A0), 2. 450 mg/kg DM of OE from Arnica montana (A450), 3. 900 mg/kg DM of OE from Arnica montana (A900), 4. 1350 mg/kg DM of OE from Arnica montana (A1350), 5. diet with 25 mg/kg DM of sodium monensin (positive control – MON). The levels of EO from Arnica montana did not alter the dry matter intake (DMI) and nutrient intake (DM, OM, CP, EE, NDF, ADF, NFC, and TDN). There was higher DM and nutrient intake for the EO from Arnica montana diets compared to MON (P < 0.05). For the comparison between MON vs. A0, there was a lower DMI and nutrients intake for MON (P < 0.05). Crude protein digestibility increased linearly (P = 0.03) in response to increasing levels of EO from Arnica montana in the diets. However, the digestibility of the other nutrients was not altered by the inclusion of EO from Arnica montana. There was no difference in nutrient digestibility for comparison between diets containing EO from Arnica montana vs. MON; and MON vs. A0. The inclusion of EO from Arnica montana in the diet linearly decreased (P = 0.03) nitrogen (N) in the urine, which was associated with a linear decrease (P = 0.03) in rumen ammonia concentration. The EO from Arnica montana contents linearly increased N retention (g/kg N intake and g/kg N absorption; P < 0.05). Diets with EO from Arnica montana had higher N intake and N excretion in urine compared to MON (P < 0.05). There was increased N retention for the diets with EO from Arnica montana when compared to MON (P = 0.02). In the contrast between MON vs. A0, there was lower N intake and lower N excretion via urine for MON (P < 0.05). The EO from Arnica montana contents conferred a quadratic effect (P = 0.03) on the molar ratio of acetate, with a lower concentration for A450. The total and individual concentrations of the other short-chain fatty acids (SCFA) were not affected by the inclusion of EO from Arnica montana. Total and individual SCFA concentrations did not differ between diets containing EO from Arnica montana vs. MON, nor between MON vs. A0. Rumen pH was not influenced by the inclusion of EO from Arnica montana in the diet, but there was a quadratic effect (P = 0.02) on the area under pH 5.5, with a greater area under 5.5 for A450. Diets with EO from Arnica montana had lower rumen pH when compared to MON (P = 0.01). The MON diet increased rumen pH compared to A0 (P < 0.01), this result contributed to a lower area under pH 5.5 and a higher total pH area for MON (P < 0.05). In conclusion, the 1350 mg/kg DM of EO from Arnica montana was the most promising, especially for the increased dietary N use efficiency, even when compared with sodium monensin.

Differential gene expression in iPSC-derived human intestinal epithelial cell layers following exposure to two concentrations of butyrate, propionate and acetate

Intestinal epithelial cells and the intestinal microbiota are in a mutualistic relationship that is dependent on communication. This communication is multifaceted, but one aspect is communication through compounds produced by the microbiota such as the short-chain fatty acids (SCFAs) butyrate, propionate and acetate. Studying the effects of SCFAs and especially butyrate in intestinal epithelial cell lines like Caco-2 cells has been proven problematic. In contrast to the in vivo intestinal epithelium, Caco-2 cells do not use butyrate as an energy source, leading to a build-up of butyrate. Therefore, we used human induced pluripotent stem cell derived intestinal epithelial cells, grown as a cell layer, to study the effects of butyrate, propionate and acetate on whole genome gene expression in the cells. For this, cells were exposed to concentrations of 1 and 10 mM of the individual short-chain fatty acids for 24 h. Unique gene expression profiles were observed for each of the SCFAs in a concentration-dependent manner. Evaluation on both an individual gene level and pathway level showed that butyrate induced the biggest effects followed by propionate and then acetate. Several known effects of SCFAs on intestinal cells were confirmed, such as effects on metabolism and immune responses. The changes in metabolic pathways in the intestinal epithelial cell layers in this study demonstrate that there is a switch in energy homeostasis, this is likely associated with the use of SCFAs as an energy source by the induced pluripotent stem cell derived intestinal epithelial cells similar to in vivo intestinal tissues where butyrate is an important energy source.

Genomic reconstruction of short-chain fatty acid production by the human gut microbiota.

Short-chain fatty acids (SCFAs) including acetate, formate, propionate, and butyrate are the end products of dietary fiber and host glycan fermentation by the human gut microbiota (HGM). SCFAs produced in the column are of utmost importance for host physiology and health. Butyrate and propionate improve gut health and play a key role in the neuroendocrine and immune systems. Prediction of HGM metabolic potential is important for understanding the influence of diet and HGM-produced metabolites on human health. We conducted a detailed metabolic reconstruction of pathways for the synthesis of SCFAs and L- and D-lactate, as additional fermentation products, in a reference set of 2,856 bacterial genomes representing strains of >800 known HGM species. The reconstructed butyrate and propionate pathways included four and three pathway variants, respectively, that start from different metabolic precursors. Altogether, we identified 48 metabolic enzymes, including five alternative enzymes in propionate pathways, and propagated their occurrences across all studied genomes. We established genomic signatures for reconstructed pathways and classified genomes according to their simplified binary phenotypes encoding the ability (“1”) or inability (“0”) of a given organism to produce SCFAs. The resulting binary phenotypes combined into a binary phenotype matrix were used to assess the SCFA synthesis potential of HGM samples from several public metagenomic studies. We report baseline and variance for Community Phenotype Indices calculated for SCFAs production capabilities in 16S metagenomic samples of intestinal microbiota from two large national cohorts (American Gut Project, UK twins), the Hadza hunter-gatherers, and the young children cohort of infants with high-risk for type 1 diabetes. We further linked the predicted SCFA metabolic capabilities with available SCFA concentrations both for in vivo fecal samples and in vitro fermentation samples from previous studies. Finally, we analyzed differential representation of individual SCFA pathway genes across several WGS metagenomic datasets. The obtained collection of SCFA pathway genes and phenotypes enables the predictive metabolic phenotype profiling of HGM datasets and enhances the in silico methodology to study cross-feeding interactions in the gut microbiomes.

Extraction optimization, structural characterization of soluble dietary fiber from Morchella importuna, and its in vitro fermentation impact on gut microbiota and short-chain fatty acids

ABSTRACT Soluble dietary fiber was extracted from spent Morchella importuna by optimizing the extraction conditions using the response surface method. Response surface analysis results indicated that the extraction yield of MI-SDF reached up to 15.38 ± 0.16% under the optimized conditions with optimal lye concentration of 2.9%, extraction temperature of 71°C and extraction time of 2 h. The results of scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction analyses suggested that M. importuna-derived soluble dietary fiber (MI-SDF) exhibited the typical porous fiber structures, polysaccharide functional groups, and cellulose crystal structure. And MI-SDF was applicable to food processing at <250°C. During in vitro fecal fermentation, MI-SDF significantly increased the abundance and diversity of beneficial bacteria and decreased those of harmful bacteria. The levels of total and individual short-chain fatty acids were significantly increased. This study will provide valuable information for further investigation of MI-SDF.

Differential Effects of Short-Chain Fatty Acids on L6 Myotube Inflammatory Mediator Production in Response to Lipopolysaccharide- or Palmitic Acid-Stimulation.

Short-chain fatty acids (SCFA) produced from dietary non-digestible carbohydrate fermentation have metabolic effects in skeletal muscle; however, their effect on inflammatory mediator production is unknown. In this study, L6 myotubes were cultured with individual SCFA (acetate, propionate, and butyrate) at 0.5 mM and 2.5 mM ± 10 ng/mL lipopolysaccharide (LPS) or ± 500 µM palmitic acid (PA) for 24 h. In response to LPS, only butyrate had an effect at the lower concentration (0.5 mM), whereas at the higher concentration (2.5 mM) both propionate and butyrate reduced MCP-1, MIP-1α, and RANTES secretion (p < 0.05), and only butyrate reduced IL-6 secretion and intracellular protein levels of phospho-STAT3 (p < 0.05). In response to PA, 0.5 mM butyrate reduced protein expression of phospho-NFκB p65 and the secretion of IL-6, MIP-1α, and MCP-1, whereas all three SCFA reduced RANTES secretion (p < 0.05). At the 2.5 mM SCFA concentration combined with PA stimulation, all three SCFA reduced intracellular protein expression of phospho-NFκB p65 and phospho-STAT3 and secreted protein levels of MCP-1, IL-6, and RANTES, whereas only butyrate reduced secretion of MIP-1α (p < 0.05). Thus, SCFA exhibit differential effects on inflammatory mediator expression in response to LPS and PA stimulation, which has implications for their individual impacts on inflammation-mediated skeletal muscle dysfunction.

Association between fecal levels of Short-Chain Fatty Acids and serum Pro- and Anti-Inflammatory Cytokines in patients with Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) represents a group of chronic inflammatory disorders characterized by dysbiosis and altered short-chain fatty acid (SCFA) level. The association between individual SCFA levels and cytokine levels is unknown. We aimed to determine the fecal SCFA levels in patients with IBD in relation to disease severity and the serum levels of pro- and anti-inflammatory cytokines. The study included 61 patients with IBD (inactive, 22; active, 39) and 16 controls. Fecal levels of organic acids (acetic, lactic, propionic, butyric, isovaleric, isobutyric, and valeric), serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), IL-17, and IL-22, complete blood count and C-reactive protein (CRP) were measured. Patients with active IBD had reduced butyric, acetic, valeric, and isovaleric acid levels and elevated lactic acid levels in stool. Hemoglobin levels were positively correlated with the levels of acetic and butyric acids (R = 0.266 and R = 0.346, respectively; P <0.05). In addition, CRP levels were inversely correlated with butyric acid levels (R = -0.573; P <0.05). Higher serum TNF-α levels were observed in patients with active IBD compared with controls (6.64 pg/ml vs 2.05 pg/ml, P <0.05). No relationship was noted between the SCFA profile and cytokine levels. The study showed that determination of SCFA levels can be used to evaluate the activity of IBD. The relationship between individual SCFA and cytokine levels seems to be complex and requires further studies.

Effects of Dietary Fibers on Short-Chain Fatty Acids and Gut Microbiota Composition in Healthy Adults: A Systematic Review.

There is an increasing interest in investigating dietary strategies able to modulate the gut microbial ecosystem which, in turn, may play a key role in human health. Dietary fibers (DFs) are widely recognized as molecules with prebiotic effects. The main objective of this systematic review was to: (i) analyze the results available on the impact of DF intervention on short chain fatty acids (SCFAs) production; (ii) evaluate the interplay between the type of DF intervention, the gut microbiota composition and its metabolic activities, and any other health associated outcome evaluated in the host. To this aim, initially, a comprehensive database of literature on human intervention studies assessing the effect of confirmed and candidate prebiotics on the microbial ecosystem was developed. Subsequently, studies performed on DFs and analyzing at least the impact on SCFA levels were extracted from the database. A total of 44 studies from 42 manuscripts were selected for the analysis. Among the different types of fiber, inulin was the DF investigated the most (n = 11). Regarding the results obtained on the ability of fiber to modulate total SCFAs, seven studies reported a significant increase, while no significant changes were reported in five studies, depending on the analytical methodology used. A total of 26 studies did not show significant differences in individual SCFAs, while the others reported significant differences for one or more SCFAs. The effect of DF interventions on the SCFA profile seemed to be strictly dependent on the dose and the type and structure of DFs. Overall, these results underline that, although affecting microbiota composition and derived metabolites, DFs do not produce univocal significant increase in SCFA levels in apparently healthy adults. In this regard, several factors (i.e., related to the study protocols and analytical methods) have been identified that could have affected the results obtained in the studies evaluated. Future studies are needed to better elucidate the relationship between DFs and gut microbiota in terms of SCFA production and impact on health-related markers.