Chain Fatty Acid Levels Research Articles

7438 DAX1/NR0B1 Related Adrenal Hypoplasia Congenita Without Hypogonadotropic Hypogonadism

Abstract Disclosure: R.L. Figueiredo: None. J.B. Drummond: None. A. Meireles: None. J.L. Machado: None. G. Vidigal: None. B.S. Rocha: None. Background: X-linked congenital adrenal hypoplasia (AHC) is a rare disease caused by genetic mutations in DXA1/NRB01 gene, which encodes a nuclear hormone receptor expressed in the adrenal cortex, gonads, hypothalamus and anterior pituitary gland, occurring in less than 1:12,500 live births (1,2). AHC is characterized by primary adrenal insufficiency (PAI) associated with hypogonadotropic hypogonadism (HH) and impaired spermatogenesis (oligospermia or azoospermia). Although DAX1/NR0B1 mutations can manifest with different phenotypes, HH is mostly present, which makes this present case a diagnostic challenge. Clinical case: A 23-year-old man presented with typical symptoms of adrenal insufficiency at the age of 7 (abdominal pain, dehydration, nausea, vomiting and cutaneous hyperpigmentation). Initial testing was consistent with primary adrenal failure: elevated ACTH levels (1250pg/mL, RR<46pg/mL) and very low serum cortisol (0.8mcg/dL, RR 3-20mcg/dL). Etiological investigation excluded autoimmune etiology (negative anti-adrenal and anti-21-hydroxylase antibodies) as well as adrenoleukodystrophy (normal very long chain fatty acid levels). Physical exam revealed normal virilization, testicular volume and penile length. The patient reported normal libido and sexual function. Hormonal evaluation showed normal total testosterone (424 and 713ng/dL, RR 165 to 753ng/dL) as well as calculated free testosterone (7.2 and 11.4ng/mL, RR>3.8ng/mL) levels. Abdominal CT showed signs of bilateral adrenal hypoplasia. We then proceeded to genetic testing that revealed a pathological variant c.625C>T:p (Gln 209*) in hemizygosity in exon 1 of the DAX 1/NR0B1 gene. This is a nonsense mutation that introduces a premature stop codon. This variant is not present on the global and Brazilian genetic databases (gnomAD and ABraOM) and has not been previously described in the literature. The patient is currently being treated for adrenal insufficiency with the lowest tolerated dose of prednisone (7.5mg/day) and fludrocortisone 0.1mg/day. Conclusion: Etiological investigation of patients with PAI is essential to understand the evolution of the disease, monitoring extra-adrenal manifestations and the possibility of genetic counseling for the family. An intact hypothalamic-pituitary gonadal axis should not preclude genetic evaluation for a DAX/NR0B1 mutation in patients with PAI and suspected AHC. Further studies will clarify if this specific mutation carries a genotype-phenotype correlation in patients with AHC without HH.

Various steaming durations alter digestion, absorption, and fermentation by human gut microbiota outcomes of Polygonatum cyrtonema Hua polysaccharides.

Different steaming durations dramatically alter the structure of Polygonatum cyrtonema polysaccharides (PCPs). This study aimed to compare characteristics of digestion, absorption, and fermentation by gut microbiota across four representative PCPs from different steaming durations (0, 4, 8, and 12 h), each with unique molecular weights and monosaccharide profiles. Chemical composition of the four PCPs was analyzed. Digestibility was evaluated using an in vitro saliva-gastrointestinal digestion model. Absorption characteristics were assessed with a Caco-2 monolayer model, and impacts on gut microbiota composition and short chain fatty acid (SCFA) levels were analyzed using in vitro fermentation with human gut microbiota. Longer steaming durations altered the chemical profiles of PCPs, reducing carbohydrate content (84.87-49.58%) and increasing levels of uronic acid (13.99-19.61%), protein (1.07-5.43%), and polyphenols (0.05-2.75%). Four PCPs were unaffected by saliva digestion but showed enhanced gastrointestinal digestibility, with reducing sugar content rising from 4.06% (P0) to 38.5% (P12). The four PCPs showed varying absorption characteristics, with P0 having the highest permeability coefficient value of 9.59 × 10-8 cm/s. However, all PCPs exhibited poor permeability, favoring gut microbiota fermentation. The four PCPs altered gut microbiota composition and elevated SCFA production, but levels declined progressively with longer steaming durations. All PCPs significantly increased the abundance of Bacteroidota, Firmicutes, and Actinobacteriota, making them the dominant bacterial phyla. Additionally, all PCPs significantly increased the abundance of Bifidobacterium, Prevotella, and Faecalibacterium compared to the control group, which, along with Bacteroides, became the dominant microbiota. Increasing the steaming duration led to a reduction in Prevotella levels, with PCPs from raw rhizomes showing the highest relative abundance at 24.90%. PCPs from moderately steamed rhizomes (4 h) led to a significant rise in Faecalibacterium (7.73%) among four PCPs. P8 and P12, derived from extensively steamed rhizomes (≥8 h), exhibited similar gut microbiota compositions, with significantly higher relative abundances of Bacteroides (20.23-20.30%) and Bifidobacterium (21.05-21.51%) compared to P0 and P4. This research highlights the importance of adjusting steaming durations to maximize the probiotic potential of P. cyrtonema polysaccharides, enhancing their effectiveness in modulating gut microbiota and SCFA levels.

Bifidobacterium longum subsp. infantis NKU FB3-14 attenuates loperamide-induced constipation through regulation of gut microbiota

Abstract Objectives Constipation is a prevalent gastrointestinal issue, and the efficacy of probiotics in alleviating constipation has been well proved. This study aimed to investigate the impact of Bifidobacterium longum subsp. infantis NKU FB3-14 on loperamide- induced constipation by focusing on improving intestinal barrier function and modulating gut microbiota composition Materials and Methods The constipated model mice induced by loperamide were treated with NKU FB3-14, and the laxative effect was assessed based on the fecal water content, first black stool time and gastrointestinal transit rate. Gastrointestinal regulatory peptides in serum, intestinal neurotransmitter and inflammatory cytokines in colon tissues were measured using ELISA kits. Changes of gut microbiota composition were analyzed through 16S ribosomal DNA sequencing identification. Additionally, HPLC detection was performed to quantify short chain fatty acids levels in feces Results Treatment with NKU FB3-14 led to increase the fecal water content, shorten the first black stool time and improve small intestine transit rate. Motilin and substance-P significantly decreased in the model group, and only motilin increased in FB3-14 group; somatostatin and vasoactive intestinal peptide were decreased in model mice and both increased in FB3-14 group; 5-HT levels in the colon tissue were upregulated following NKU FB3-14 treatment. Histological examination revealed thinner colonic mucosa in the model group along with significant in TNF-α, IL-1β and IL-17 levels form the colon tissues which were all relieved by NKU FB 3-14 treatment. Furthermore, NKU FB3-14 intervention resulted in reduced abundance of Desulfobacterota and Desulfovibrio while increasing the abundance of Ruminococcaceae and Eubacterium; higher level of butyric acid was observed in feces Conclusions In summary, our findings demonstrated that NKU FB3-14 treatment significantly enhanced the intestinal motility, regulated the expression levels of gastrointestinal regulatory peptides, prevented damage to colonic barriers as well as ameliorated gut microbiota imbalance associated with loperamide-induced constipation.

Abstract P379: High Fiber Diet Attenuates Age-dependent Hypertension, Gut Dysbiosis, and Cognitive Impairment in Male Sprague Dawley Rats

Hypothesis: Gut dysbiosis contributes to age-dependent hypertension (HTN) driven cognitive impairment (CI), that is attenuated by prebiotic dietary fiber supplementation. Methods: In 3 and 16 month old (M) male Sprague Dawley rats, 3M rats receiving a fecal microbiota transplant (FMT) from 16M rats, and 16M rats fed a 6 week high prebiotic fiber (HPF) diet (n=4-6), BP, cognition (novel object recognition), paraventricular nucleus (PVN) and hippocampal blood brain barrier (BBB) integrity (FITC extravasation) and neuroinflammation (IBA1 and GFAP), gut microbiota taxonomy (by WGS) and short chain fatty acid (SCFA) levels (by GC-MS) were assessed. Results: 16M rats exhibit gut dysbiosis, HTN, hippocampal BBB disruption and neuroinflammation, and CI. FMT to 3M rats evoked HTN and gut dysbiosis (3M vs 3M + FMT: Cecal Bray-Curtis b diversity PCoA Species Bacteria, P=<0.05). Linear Discriminant Analysis shows enrichment of cecal a) Lactobacillales (associated with lower BP) in 3M rats (LDA Log 10 4.69, P=0.022), b) Alistipes putrendenis in 16M rats (LDA Log 10 3.98, P=0.005), c) the Bacteroides genera (increased in HTN) in 3M + FMT rats (LDA Log 10 4.34, P=0.015). HPF attenuated gut dysbiosis (16M vs 16M + HPF: Fecal Bray-Curtis b Diversity PCoA Species Bacteria, P<0.05, PCoA MetaCyc, P<0.05; 16M pre vs post HPF: Fecal Bray-Curtis b Diversity PCoA Species Bacteria, P<0.05), increased SCFA levels, reduced BP, and improved PVN and hippocampal BBB disruption, hippocampal neuroinflammation and CI. Conclusions: Gut dysbiosis contributes to age-dependent HTN-driven CI. HPF supplementation, a readily implementable lifestyle intervention, attenuates HTN-driven CI via mechanisms independent of current antihypertensive medications.

Neuromotor decline is associated with gut dysbiosis following surgical decompression for Degenerative Cervical Myelopathy

Degenerative cervical myelopathy (DCM) describes a spectrum of disorders that cause progressive and chronic cervical spinal cord compression. The clinical presentation can be complex and can include locomotor impairment, hand and upper extremity dysfunction, pain, loss of bladder and bowel function, as well as gastrointestinal dysfunction. Once diagnosed, surgical decompression is the recommended treatment for DCM patients with moderate to severe impairment.Our body is composed of a large community of microorganisms, known as the microbiota. Traumatic and non-traumatic spinal cord injuries (SCIs) can induce changes in the gut microbiota and gut microbiota derived metabolites. These changes have been reported as important disease-modifying factors after injury. However, whether gut dysbiosis is associated with functional neurological recovery after surgical decompression has not been examined to date.Here, DCM was induced in C57BL/6 mice by implanting an aromatic polyether material underneath the C5–6 laminae. The extent of gut dysbiosis was assessed by gas chromatography and 16S rRNA sequencing from fecal samples before and after decompression. Neuromotor activity was assessed using the Catwalk test.Our results show that DCM pre- and post- surgical decompression is associated with gut dysbiosis, without altering short chain fatty acids (SCFAs) levels. Significant differences in Clostridia, Verrumicrobiae, Lachnospiracea, Firmicutes, Bacteroidales, and Clostridiaceae were observed between the DCM group (before decompression) and after surgical decompression (2 and 5 weeks). The changes in gut microbiota composition correlated with locomotor features of the Catwalk. For example, a longer duration of ground contact and dysfunctional swing in the forelimbs, were positively correlated with gut dysbiosis. These results show for the first time an association between gut dysbiosis and locomotor deterioration after delayed surgical decompression. Thus, providing a better understanding of the extent of changes in microbiota composition in the setting of DCM pre- and post- surgical decompression.

Perspectives on carboxylates generation from Ecuadorian agro-wastes

Carboxylates generation from banana (peel and pulp), coffee, and cacao fermentation agro-waste, upon uncontrolled and controlled pHs of 6.6 (heat-driven methanogens inactivation) and 5.2 (pH inactivation), was studied. Regarding volatile fatty acids (VFAs), acetic was the highest for cocoa (96.2 g kg−1TVS) at pH 4.5. However, butyric was relevant for banana pulp (90.7 g kg−1TVS), at controlled pH 6.6. The highest medium chain fatty acid (MCFAs) level was hexanoic (cocoa, 3.5 g kg−1TVS), while octanoic reached a maximum of 2.8 g kg−1TVS for coffee at pH 6.6. At pH 5.2 MCFAs yield was relatively low. Uncontrolled pH conditions, using banana resulted in superior VFAs production compared to controlled conditions. Thus, pH became a determining variable when deciding the time and kind of carboxylic acid to be recovered. The bacterial community at the end of the chain elongation process was dominated by phyla Firmicutes, and Clostridium as the most common genera.

Colon impairments and inflammation driven by an altered gut microbiota leads to social behavior deficits rescued by hyaluronic acid and celecoxib.

The exact mechanisms linking the gut microbiota and social behavior are still under investigation. We aimed to explore the role of the gut microbiota in shaping social behavior deficits using selectively bred mice possessing dominant (Dom) or submissive (Sub) behavior features. Sub mice exhibit asocial, depressive- and anxiety-like behaviors, as well as systemic inflammation, all of which are shaped by their impaired gut microbiota composition. An age-dependent comparative analysis of the gut microbiota composition of Dom and Sub mice was performed using 16S rRNA sequencing, from early infancy to adulthood. Dom and Sub gastrointestinal (GI) tract anatomy, function, and immune profiling analyses were performed using histology, RT-PCR, flow cytometry, cytokine array, and dextran-FITC permeability assays. Short chain fatty acids (SCFA) levels in the colons of Dom and Sub mice were quantified using targeted metabolomics. To support our findings, adult Sub mice were orally treatedwith hyaluronic acid (HA) (30 mg/kg) or with the non-steroidal anti-inflammatory agent celecoxib (16 mg/kg). We demonstrate that from early infancy the Sub mouse gut microbiota lacks essential bacteria for immune maturation, including Lactobacillus and Bifidobacterium genera. Furthermore, from birth, Sub mice possess a thicker colon mucin layer, and from early adulthood, they exhibit shorter colonic length, altered colon integrity with increased gut permeability, reduced SCFA levels and decreased regulatory T-cells, compared to Dom mice. Therapeutic intervention in adult Sub mice treated with HA, celecoxib, or both agents, rescued Sub mice phenotypes. HA treatment reduced Sub mouse gut permeability, increased colon length, and improved mouse social behavior deficits. Treatment with celecoxib increased sociability, reduced depressive- and anxiety-like behaviors, and increased colon length, and a combined treatment resulted in similar effects as celecoxib administered as a single agent. Overall, our data suggest that treating colon inflammation and decreasing gut permeability can restore gut physiology and prevent social deficits later in life. These findings provide critical insights into the importance of early life gut microbiota in shaping gut immunity, functionality, and social behavior, and may be beneficial for the development of future therapeutic strategies.

Disordered GPR43/NLRP3 expression in peripheral leukocytes of patients with atrial fibrillation is associated with intestinal short chain fatty acids levels

BackgroundAtrial fibrillation (AF) is associated with circulating inflammation. Short-chain fatty acids (SCFAs) derived from gut microbiota (GM) regulate leukocyte function and inhibit the release of inflammatory cytokines, which are partly mediated by the G-protein-coupled receptor 43 (GPR43) signaling. This study aimed to investigate the expression of GPR43/NOD-like receptors family pyrin domain containing 3 (NLRP3) in leukocytes and the interaction with intestinal SCFAs levels in AF patients.MethodsExpressions of GPR43 and NLRP3 mRNA in peripheral blood leukocytes from 23 AF patients and 25 non-AF controls were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Expressions of leukocyte GPR43 and NLRP3 protein were evaluated by western blot analysis. The levels of plasma IL-1β were measured by enzyme-linked immunosorbent assay (ELISA). The fecal SCFAs levels based on GC/MS metabolome of corresponding 21 controls and 14 AF patients were acquired from our published dataset. To evaluate the expression of NLRP3 and GPR43 and the release of IL-1β, human THP-1 cells were stimulated with or without SCFAs (acetate, propionate, and butyrate), lipopolysaccharide (LPS), and nigericin in vitro, respectively.ResultsCompared to the controls, the mRNA expression in peripheral leukocytes was significantly reduced in AF patients (P = 0.011) coupled with the increase in downstream leukocyte NLRP3 mRNA expression (P = 0.007) and plasma IL-1β levels (P < 0.001), consistent with changes in GPR43 and NLRP3 protein expression. Furthermore, leukocyte GPR43 mRNA levels were positively correlated with fecal GM-derived acetic acid (P = 0.046) and negatively correlated with NLRP3 mRNA expression (P = 0.024). In contrast to the negative correlation between left atrial diameter (LAD) and GPR43 (P = 0.008), LAD was positively correlated with the leukocyte NLRP3 mRNA levels (P = 0.024). Subsequent mediation analysis showed that 68.88% of the total effect of intestinal acetic acid on AF might be mediated by leukocyte GPR43/NLRP3. The constructed GPR43–NLRP3 score might have a predictive potential for AF detection (AUC = 0.81, P < 0.001). Moreover, SCFAs treatment increased GPR43 expression and remarkably reduced LPS/nigericin-induced NLRP3 expression and IL-1β release in human THP-1 cells in vitro.ConclusionsDisrupted interactions between GPR43 and NLRP3 expression in peripheral blood leukocytes, associated with reduced intestinal GM-derived SCFAs, especially acetic acid, may be involved in AF development and left atrial enlargement by enhancing circulating inflammation.

Enzymatic hydrolysates from sea cucumber body wall prevent low calcium-induced osteoporosis by regulating calcium absorption and gut microbiota

Inadequate calcium intake or intestinal malabsorption is closely related to osteoporosis. The aim of this study was to investigate the effects of sea cucumber enzymatic hydrolysates (SCEH) prepared from body wall on calcium absorption in calcium-deficient rats. Fifty-six female Sprague-Dawley rats on a low calcium diet that induced osteoporosis were fed SCEH and calcium carbonate for 3 months. The results showed that oral administration of SCEH and calcium carbonate both increased the body weight (bw) and bone mineral density (BMD) in calcium-deficient rats to varying degrees, thereby alleviating the adverse effects of osteoporosis. In addition, oral administration of a combination of SCEH (2000 mg/kg bw/day) and calcium (333 mg/kg bw/day) upregulated the expression of calcium transporter genes (TRPV6 and Calbindin-D9k) in the intestines, increased serum 1,25(OH)2D3 levels and BMD, decreased trabecular bone separation, and inhibited parathyroid hormone (PTH) release in calcium-deficient rats compared to calcium carbonate groups. Thus, this combination promoted calcium absorption and improved the efficiency of calcium utilization. These results might be associated with a higher short chain fatty acid (SCFA) level in the gut and an increased abundance of butyrate and acetate producing bacteria, such as Christensenellaceae R7 group, UCG-005 and Clostridium UCG-014. Therefore, a diet containing SCEH and calcium combinations might be recommended to increase bone mass and inhibit osteoporosis.

Ameliorating effect of 2′-fucosyllactose and 6′-sialyllactose on lipopolysaccharide-induced intestinal inflammation

Human milk oligosaccharides (HMO) affect gut microbiota during neonatal development, particularly with respect to the immune system. Bovine milk-based infant formulas have low oligosaccharide contents. Thus, efforts to fortify infant formulas with HMO are being undertaken. Two major HMO, 2'-fucosyllactose (2'-FL) and 6'-sialyllactose (6'-SL), exert anti-inflammatory effects; however, the associations between anti-inflammatory effects induced by 2'-FL and 6'-SL co-treatment and gut microbiota composition and metabolite modulation remain unclear. Therefore, in this study, we evaluated the effects of a mixture of these HMO. To determine the optimal HMO ratio for anti-inflammatory effects and elucidate its mode of action, LPS-induced inflammatory HT-29 epithelial cells and intestinal inflamed suckling mice were treated with various mixtures of 2'-FL and 6'-SL. 2'-FL:6'-SL ratio of 5:1 was identified as the most effective pre-treatment HMO mixture in vitro; thus, this ratio was selected and used for low, middle, and high-dose treatments for subsequent in vivo studies. In vivo, high-dose HMO treatment restored LPS-induced inflammation symptoms, such as body weight loss, colon length reduction, histological structural damage, and intestinal gene expression related to inflammatory responses. High-dose HMO was the only treatment that modulated the major phyla Bacteroidetes and Firmicutes and the genera Ihubacter, Mageeibacillus, and Saccharofermentans. These changes in microbial composition were correlated with intestinal inflammation-related gene expression and short-chain fatty acid production. To our knowledge, our study is the first to report the effects of Ihubacter, Mageeibacillus, and Saccharofermentans on short chain fatty acid levels, which can subsequently affect inflammatory cytokine and tight junction protein levels. Conclusively, the HMO mixture exerted anti-inflammatory effects through changes in microbiota and metabolite production. These findings suggested that supplementation of infant formula with HMO may benefit formula-fed infants by forming unique microbiota contributing to neonatal development.

Long chain monomethyl branched-chain fatty acid levels in human milk vary with gestational weight gain

Breastfeeding is an important determinant of infant health and there is immense interest in understanding its metabolite composition so that key beneficial components can be identified. The aim of this research was to measure the fatty acid composition of human milk in an Irish cohort where we examined changes depending on lactation stage and gestational weight gain trajectory. Utilizing a chromatography approach optimal for isomer separation, we identified 44 individual fatty acid species via GCMS and showed that monomethyl branched-chain fatty acids(mmBCFA's), C15:0 and C16:1 are lower in women with excess gestational weight gain versus low gestational weight gain. To further explore the potential contribution of the activity of endogenous metabolic pathways to levels of these fatty acids in milk, we administered D2O to C57BL/6J dams fed a purified lard based high fat diet (HFD) or low-fat diet during gestation and quantified the total and de novo synthesized levels of fatty acids in their milk. We found that de novo synthesis over three days can account for between 10 and 50 % of mmBCFAs in milk from dams on the low-fat diet dependent on the branched-chain fatty acid species. However, HFD fed mice had significantly decreased de novo synthesized fatty acids in milk resulting in lower total mmBCFAs and medium chain fatty acid levels. Overall, our findings highlight the diverse fatty acid composition of human milk and that human milk mmBCFA levels differ between gestational weight gain phenotypes. In addition, our data indicates that de novo synthesis contributes to mmBCFA levels in mice milk and thus may also be a contributory factor to mmBCFA levels in human milk. Given emerging data indicating mmBCFAs may be beneficial components of milk, this study contributes to our knowledge around the phenotypic factors that may impact their levels.

Fatty acid metabolism promotes TRPV4 activity in lung microvascular endothelial cells in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a morbid disease characterized by significant lung endothelial cell (EC) dysfunction. Prior work has shown that microvascular endothelial cells (MVECs) isolated from animals with experimental PAH and patients with PAH exhibit significant abnormalities in metabolism and calcium signaling. With regards to metabolism, we and others have shown evidence of increased aerobic glycolysis and evidence of increased utilization of alternate fuel sources (such as fatty acids) in PAH EC. In the realm of calcium signaling, our prior work linked increased activity of the transient receptor potential vanilloid-4 (TRPV4) channel to increased proliferation of MVECs isolated from the Sugen/Hypoxia rat model of PAH (SuHx-MVECs). However, the relationship between metabolic shifts and calcium abnormalities was not clear. Specifically, whether shifts in metabolism were responsible for increasing TRPV4 channel activity in SuHx-MVECs was not known. In this study, using human data, serum samples from SuHx rats, and SuHx-MVECs, we describe the consequences of increased MVEC fatty acid oxidation in PAH. In human samples, we observed an increase in long-chain fatty acid levels that was associated with PAH severity. Next, using SuHx rats and SuHx-MVECs, we observed increased intracellular levels of lipids. We also show that increasing intracellular lipid content increases TRPV4 activity, whereas inhibiting fatty acid oxidation normalizes basal calcium levels in SuHx-MVECs. By exploring the fate of fatty acid-derived carbons, we observed that the metabolite linking increased intracellular lipids to TRPV4 activity was β-hydroxybutyrate (BOHB), a product of fatty acid oxidation. Finally, we show that BOHB supplementation alone is sufficient to sensitize the TRPV4 channel in rat and mouse MVECs. Returning to humans, we observe a transpulmonary BOHB gradient in human patients with PAH. Thus, we establish a link between fatty acid oxidation, BOHB production, and TRPV4 activity in MVECs in PAH. These data provide new insight into metabolic regulation of calcium signaling in lung MVECs in PAH.NEW & NOTEWORTHY In this paper, we explore the link between metabolism and intracellular calcium levels in microvascular endothelial cells (MVECs) in pulmonary arterial hypertension (PAH). We show that fatty acid oxidation promotes sensitivity of the transient receptor potential vanilloid-4 (TRPV4) calcium channel in MVECs isolated from a rodent model of PAH.

Effects of cumin, coriander, and sichuan pepper on microbiota and the antioxidant capacities of human faecal cultures

Spices have been reported to have several health-promoting effects. In this study, we investigated the effects of cumin seeds (CM), coriander seeds (CR), and Sichuan pepper (HJ) on human gut microbiota using human stool samples from healthy volunteers. The samples were incubated with or without addition of these spices, and the microbiota were analysed using 16S rRNA (V4) gene amplicon sequencing. After anaerobic fermentation for 24 h, pH was slightly lowered under HJ addition, although this varied across individuals. Acetate, propionate, and total short chain fatty acid levels increased under CM and CR addition. Indole content was low in cultures with HJ. Fermentation of the faecal samples increased in vitro superoxide anion (O2-) radical-scavenging and Fe-reducing capacities under CM and CR addition, although antioxidant capacities were still higher in cultures with HJ. Genera regarded as butyrate producers (Faecalibacterium and Roseburia) were high in HJ cultures, but the genera, species, and amplicon sequence variants of butyrate producers were different across individuals. In contrast, Enterobacteriaceae presence was lowered with CM and HJ addition. These results suggest that compounds contained in the investigated spices, particularly in HJ, which reach the human colon affect the gut microbiota. Further studies on the mechanisms of the interaction between spice components and spice-responsive gut indigenous bacteria, both desirable (butyrate producers) and undesirable (inflammation-related commensals), are needed.

Abstract P166: Prebiotic Dietary Fiber Supplementation Attenuates Gut Microbiota Dysbiosis And Age-dependent Hypertension-driven Cognitive Impairment

Hypothesis: Gut microbiota dysbiosis contributes to age-dependent hypertension (HTN) driven cognitive impairment (CI), which is attenuated by prebiotic dietary fiber supplementation. Methods: In 3 and 16 month (M) male Sprague Dawley rats, 3M rats receiving a fecal microbiota transplant (FMT) from 16M rats, and 16M rats fed a 6 week high prebiotic fiber (HPF) diet (n=4-6), BP, cognitive function (novel object recognition), hippocampal blood brain barrier (BBB) integrity (by FITC extravasation), gut microbiota taxonomy (by WGS) and short chain fatty acid (SCFA) levels (by GC-MS) were assessed. Results: Aged 16M rats exhibit gut microbiota dysbiosis, HTN, hippocampal BBB leakage and impaired cognition. FMT to 3M rats evoked gut microbiota dysbiosis (3M vs 3M + FMT: Cecal Bray-Curtis β diversity PCoA Species Bacteria, P=&lt;0.05) and HTN. Linear Discriminant Analysis shows enrichment of cecal a) Lactobacillales (associated with lower BP) in 3M rats (LDA Log 10 4.69, P=0.022), b) Alistipes putrendenis in 16M rats (LDA Log 10 3.98, P=0.005), c) the Bacteroides genera (increased in HTN) in 3M + FMT rats (LDA Log 10 4.34, P=0.015). HPF attenuated gut microbiota dysbiosis (16M vs 16M + HPF: Fecal Bray-Curtis β Diversity PCoA Species Bacteria, P&lt;0.05, PCoA MetaCyc, P&lt;0.05; 16M pre vs post HPF: Fecal Bray-Curtis β Diversity PCoA Species Bacteria, P&lt;0.05), increased SCFA levels, reduced BP and hippocampal BBB permeability and improved cognition. Conclusions: Gut microbiota dysbiosis contributes to age-dependent HTN-driven CI. HPF supplementation, a readily implementable lifestyle intervention, attenuates HTN driven CI via mechanisms independent of current antihypertensive medications.

SLC9A5 promotes tumor growth and cell motility via ACOX1-mediated peroxisomal fatty acid oxidation

Growing evidence suggests a strong association between decreased lipid catabolism and the development of cancer. Solute carrier family 9 member A5 (SLC9A5) plays a regulatory role in colorectal function. However, the specific involvement of SLC9A5 in colorectal cancer (CRC) remains unclear, as well as its potential connection to lipid catabolism. We found that SLC9A5 exhibited significantly higher expression in CRC tumor tissues compared to adjacent paratumor tissues, as confirmed through analysis of the TCGA database and validation on a CRC tissue chip using IHC. Furthermore, in vitro experiments showed that knockdown of SLC9A5 resulted in suppressed cell proliferation, migration, and invasion. Then we performed bioinformatics analysis and found that SLC9A5 was significantly enriched in peroxisomal fatty acid oxidation (FAO) pathway and negatively correlated with its first rate-limiting enzyme acyl-CoA oxidases (ACOX). Interestingly, the expression of ACOX1, as well as FAO process indicated by changes in very long chain fatty acid levels, were enhanced upon SLC9A5 knockdown in CRC cells. Moreover, the attenuated tumor growth, migration, invasion, and increased FAO observed after SLC9A5 knockdown could be reversed by simultaneous knockdown of both SLC9A5 and ACOX1. In summary, these findings reveal the oncogenic role of SLC9A5 in CRC, particularly in relation to ACOX1-mediated peroxidation, and might serve as a promising therapeutic target for inhibiting the progression of colorectal cancer.

Clinical trial of a probiotic and herbal supplement for lung health.

Dysbiosis of the gut microbiome may augment lung disease via the gut-lung axis. Proteobacteria may contribute to tissue proteolysis followed by neutrophil recruitment, lung tissue injury, and perpetuation of chronic inflammation. To study the effects of probiotics across the gut-lung axis, we sought to determine if a Lactobacillus probiotic and herbal blend was safe and well-tolerated in healthy volunteers and asthmatic patients. We conducted a 1-month randomized, open-label clinical trial in Cork, Ireland with healthy and asthmatic patients who took the blend twice a day. The primary endpoint was safety with exploratory endpoints including quality of life, lung function, gut microbiome ecology, and inflammatory biomarkers. All subjects tolerated the blend without adverse events. Asthmatic subjects who took the blend showed significant improvements in lung function as measured by forced expiratory volume and serum short chain fatty acid levels from baseline to Week 4. The gut microbiome of asthmatic subjects differed significantly from controls, with the most prominent difference in the relative abundance of the proteobacteria Escherichia coli. Administration of the probiotic maintained overall microbial community architecture with the only significant difference being an increase in absolute abundance of the probiotic strains measured by strain-specific PCR. This study supports the safety and efficacy potential of a Lactobacillus probiotic plus herbal blend to act on the gut-lung axis. However, due to the lack of a control group, a longer blinded, placebo-controlled study will be warranted to confirm the efficacy improvements observed in this trial. https://clinicaltrials.gov/, identifier NCT05173168.

Evaluation of plasma Short chain fatty acid levels as markers for Inflammatory bowel disease

Background Specific variations of short chain fatty acids in fecal samples have been shown for patients with inflammatory bowel disease. The aim of this study was to assess if Crohn’s disease and ulcerative colitis are associated with altered concentrations of short chain fatty acids also in blood plasma. Method Between 2016-2019, Swedish adults referred to a tertiary center for colonoscopy were asked to participate in a cross-sectional study. Individuals with Crohn’s disease or ulcerative colitis as well as individuals with no findings on the colonoscopy (defined as clean colon) were included in the study. Data on colonoscopy findings, blood samples (including haemoglobin, C-reactive protein and short chain fatty acid analysis) as well as a validated lifestyle questionnaire including 277 questions were collected from all participants. Linear regression was used to compare mean concentrations of short chain fatty acids between Crohn’s disease, ulcerative colitis and clean colon. Results The cohort consisted of 132 individuals with Crohn’s disease, 119 with ulcerative colitis and 205 with clean colon. In the crude model, succinic acid was significantly lower (p < 0.05) among patients with Crohn’s disease (mean 3.00 µM SE 0.10) and ulcerative colitis (mean 3.13 µM SE 0.10) in comparison to clean colon (mean 3.41 µM SE 0.08), however when adjusting for sex, age and diet the results did not remain statistically significant. No differences in plasma concentration of the other measured short chain fatty acids were detected. Conclusion Crohn’s disease and ulcerative colitis are not associated with altered short chain fatty acid concentrations in plasma. Further research is needed to confirm or refute our findings.

Modulation of the gut microbiome with nisin

Nisin is a broad spectrum bacteriocin used extensively as a food preservative that was identified in Lactococcus lactis nearly a century ago. We show that orally-ingested nisin survives transit through the porcine gastrointestinal tract intact (as evidenced by activity and molecular weight determination) where it impacts both the composition and functioning of the microbiota. Specifically, nisin treatment caused a reversible decrease in Gram positive bacteria, resulting in a reshaping of the Firmicutes and a corresponding relative increase in Gram negative Proteobacteria. These changes were mirrored by the modification in relative abundance of pathways involved in acetate, butyrate (decreased) and propionate (increased) synthesis which correlated with overall reductions in short chain fatty acid levels in stool. These reversible changes that occur as a result of nisin ingestion demonstrate the potential of bacteriocins like nisin to shape mammalian microbiomes and impact on the functionality of the community.

Candida expansion in the gut of lung cancer patients associates with an ecological signature that supports growth under dysbiotic conditions

Candida species overgrowth in the human gut is considered a prerequisite for invasive candidiasis, but our understanding of gut bacteria promoting or restricting this overgrowth is still limited. By integrating cross-sectional mycobiome and shotgun metagenomics data from the stool of 75 male and female cancer patients at risk but without systemic candidiasis, bacterial communities in high Candida samples display higher metabolic flexibility yet lower contributional diversity than those in low Candida samples. We develop machine learning models that use only bacterial taxa or functional relative abundances to predict the levels of Candida genus and species in an external validation cohort with an AUC of 78.6–81.1%. We propose a mechanism for intestinal Candida overgrowth based on an increase in lactate-producing bacteria, which coincides with a decrease in bacteria that regulate short chain fatty acid and oxygen levels. Under these conditions, the ability of Candida to harness lactate as a nutrient source may enable Candida to outcompete other fungi in the gut.

Synergistic antidepressant-like effect of n-3 polyunsaturated fatty acids and probiotics through the brain-gut axis in rats exposed to chronic mild stress

N-3 polyunsaturated fatty acids (PUFA) and probiotics have antidepressant-like effects, but the underlying mechanisms are unclear. We hypothesized that n-3 PUFA combined with live and dead probiotics synergistically improves depression by modulating the hypothalamic-pituitary-adrenal (HPA) axis and serotonergic pathways through the brain-gut axis. Rats were randomly divided into seven groups (n = 8/group): nonchronic mild stress (CMS) with n-6 PUFA, CMS with n-3 PUFA, n-6 PUFA, live probiotics, dead probiotics, n-3 PUFA, and live probiotics, and n-3 PUFA and dead probiotics. Diets of n-6 and n-3 PUFA and oral supplementation of live and dead probiotics were provided for 12 weeks, and CMS was performed for the last 5 weeks. N-3 PUFA and probiotics improved depressive behaviors and modulated the brain and gut HPA axis by synergistically increasing glucocorticoid receptor expression and decreasing corticotropin-releasing factor expression and blood levels of adrenocorticotropic hormone and corticosterone. N-3 PUFA and probiotics upregulated the brain serotonergic pathway through serotonin levels and expression of brain-derived neurotrophic factor, phosphorylated cAMP response binding protein, and 5-hydroxytryptamine 1A receptor while downregulating the gut serotonergic pathway. Furthermore, n-3 PUFA and probiotics increased the abundance of Ruminococcaceae, brain and gut short chain fatty acid levels, and occludin expression while decreasing the expression of tumor necrosis factor-α, interleukin-1β, and prostaglandin E2 and blood lipopolysaccharides levels. There was no significant difference between the live and dead probiotics. In conclusion, n-3 PUFA and probiotics had synergistic antidepressant-like effects on the HPA axis and serotonergic pathways of the brain and gut through the brain-gut axis.