Roughage Research Articles

Inulin alleviates offspring asthma by altering maternal intestinal microbiome composition to increase short-chain fatty acids.

Technically, symptom of offspring asthma is also closely reliant on its maternal high-fiber diet as well as the intestinal microbiome. Fruits and vegetables are abundant in inulin, and this naturally soluble dietary fiber is endowed with a potential value on offspring asthma control through the maternal intake, but the mechanism now remains less studied. In this study, rats were given with inulin-included drinking water, whereas in normal group rats were allowed with normal water. Afterwards, we analyzed both the formations of the offspring intestinal microbiome ahead of asthma model establishment and of the maternal intestinal microbiome through high throughput sequence and the short-chain fatty acids (SCFAs) by metabolomic analysis. Subsequently, lung inflammation indexes were detected by Elisa, and the expression of short-chain fatty acid receptors (GPR41, GPR43) in the offspring of asthma models were evaluated through qPCR assay. Inulin intake resulted in altered maternal intestinal microbiome composition, with a significant increase in SCFAs-producing bacteria (mainly Bifidobacterium), attenuating the asthmatic inflammatory response in the offspring. Meanwhile, inulin intake during pregnancy modulates the composition of the intestinal microbiome of the offspring, and this alteration appears before the onset of asthma, hence, there should be further studies onto the impacts of offspring's intestinal microbiome on asthma procession.

Gut microbiota fermentation profiles of pre-digested mycoprotein (Quorn) using faecal batch cultures in vitro: a preliminary study

High-fibre diets are beneficial for many health outcomes via a wide range of mechanisms including gut microbiota fermentation-derived short-chain fatty acid (SCFAs) production. Mycoprotein (marketed as Quorn) is a food high in fibre (>6 g/100 g wet weight (ww)) and protein (13 g/100 g ww) which has been shown to have positive effects on glycemic control and appetite in humans. Nevertheless, the mechanisms underpinning this are poorly understood. Here, we investigate the changes in gut microbiota α- and β-diversity, pH and SCFAs production in faecal batch cultures supplemented with pre-digested mycoprotein (Quorn), soy, chicken and control (unsupplemented) using eight fresh stools from healthy donors. The results showed that pre-digested mycoprotein did not alter pH (p = .896), α- or β-diversity of the gut microbiota when compared to the control, soy, and chicken. Nevertheless, chicken led to a significant increase in total SCFAs post-24 h vs. control (+57.07 mmol/L, p = .01). In particular, propionate increased when compared to soy (+19.59 mmol/L, p = .03) and the control (+23.19 mmol/L, p < .01). No other differences in SCFAs were detected. In conclusion, pre-digested mycoprotein was not fermented in vitro by healthy gut microbiota in the settings of this experiment.

Solitary rectal ulcer syndrome – An uncommon cause of rectal bleeding in children

Background: Solitary rectal ulcer syndrome (SRUS) is a benign chronic disorder rarely found in children commonly presents with rectal bleeding, mucorrhea, straining during defecation, tenesmus, feeling of incomplete defecation, rectal prolapse and constipation. The pathogenesis is not clearly understood but several factors such as trauma, rectal prolapse, ischemia, behavioral disorders such as excessive straining during defecation and rectal manipulation, sexual abuse and disharmony of the pelvic floor muscles during defection may be involved. SRUS is diagnosed on the basis of clinical symptoms and endoscopic and histological findings. Various treatment protocol for SRUS have been described such as conservative management such as family reassurance, regulation of toilet habits, avoidance of straining, encouragement of a high-fiber diet, topical treatments with salicylate, sulfasalazine, steroids and sucralfate, and surgery. Methods: A comprehensive search is done using PubMed, Scopus, Google scholar and MEDLINE. Results: The result of this review will be published in a journal. Conclusion: This study discusses about the pathogenesis, clinical features, diagnosis and various treatment strategy of solitary rectal ulcer syndrome in children. Bangladesh Medical Res Counc Bull 2023; 49(1): 70-74

Biodegraded hay with graded addition of Pleurotus ostreatus improves dry matter disappearance and reduces methane production of diets incubated in vitro

Bioconversion of plant material with white-rot fungi has demonstrated improvements in in vitro digestibility, however, effects on rumen fermentation parameters and methane (CH4) production, when included as a dietary ingredient, are not clear. The aim of this study was to assess changes in rumen fermentation parameters and in vitro CH4 production by dietary inclusion of ryegrass-fescue hay biodegraded with P. ostreatus (H-PO) during 14 days of solid fermentation. The experiment used 2 diets with contrasting acid detergent fibre (aADFom) content which were added with 0, 3 and 6% H-PO. Substrates were incubated 3 times with sampling at 24 h. Results were analysed by ANOVA, and compared with Tukey’s test and polynomial contrasts. Inclusion of H-PO at concentrations of 3 and 6% resulted in increased in vitro dry matter (DM) disappearance (IVDMD) by 10 and 12% respectively, whereas high concentrations of aADFom reduced IVDMD by 10% as compared to low aADFom. Methane production (mg/g DM incubated) and yield (mg/g DM degraded) were reduced by increasing aADFom and P. ostreatus biodegraded hay concentrations in the diets (p < 0.001) whereas concentrations of total short-chain fatty acids were not affected by the inclusion of biodegraded hay (p = 0.080) or aADFom concentration (p = 0.076). Increasing concentrations of biodegraded hay resulted in increased acetate (p < 0.001), and reduced propionate proportions (p = 0.021) but did not affect butyrate (p = 0.233). In conclusion the use of biodegraded hay as a pre-treated ingredient improved the utilisation of low and high fibre diets by increasing the in vitro disappearance, and decreasing CH4 emissions, without increasing the propionate proportion. HIGHLIGHTS The use of hay biodegraded with P. ostreatus (H-PO) improves the digestibility of ruminant diets. The use of H-PO decreases methane, and increases acetate production in in vitro conditions. The use of H-PO as an ingredient in ruminant diets could improve the sustainability of livestock systems.

To Identify the Risk Factors of Sigmoid Volvulus In Central India Tribal Area Population

Background: Sigmoid volvulus is a condition in which the torsion of the sigmoid colon around its mesenteric axis leads to acute colonic obstruction that is not timely and properly treated, leading to life-threatening and morbid complications such as bowel ischemia, gangrene and perforation. The aim of the study is to analyze the risk factor of SV, clinical signs and symptoms, treatment, complications and outcomes when it presents as a surgical emergency in a tribal area in central India. Methods: This is a prospective, single-center, cohort study of 24 patients presenting to the government with features of SV. medical college Shahdol [tribal area of central India] from June 2022 to November 2022. All data formulated in frequency charts. Results: we develop a prediction model for the high incidence of SV, its presentation and treatment in patients from the trunk region. 21 patients (87.5%) were male and 3 patients (12.5%) were female. The age of the patients varied between 30-80 years, most of them between 50-70 years. The main risk factors were [1] old age, [2] male gender, [3] rural residence, [4] low socioeconomic status, [5] pure vegetarian diet, [6] abuse [mc-alcohol], [7] chronic constipation, [8] chronic pain medication user [9] associated comorbidity [mc-hypertension] [10] high fiber diet, have a higher chance of this. The most common symptoms were absolute constipation and generalized abdominal distension followed by abdominal pain. The most common symptoms were tenderness followed by tachycardia and then fever. All patients were examined by clinical symptoms, plain X-ray of the upright abdomen and blood tests. Vomiting, the most common postoperative complication, followed paralytic ileus. Among the patients, 6 had distended gangrenous SV, 15 patients were found to have distended non-gangrenous, and 3 patients had perforated gangrenous sigmoid colon volvulus. Mostly treated with sigmoidectomy with stoma followed by resection with colorectal anastomosis with flatus bypass. Most patients were discharged, only 3 [12.8%] patients died. Conclusions: SV predominates in older men. Most patients with SV have a history of alcohol abuse, a high-fiber diet, and low socioeconomic status.

Supplementing oat hulls to the diet of suckling piglets altered their intestinal tract and colonic microbiota development.

Current study evaluated the effect of a fine and coarsely ground insoluble dietary fibre source on the gastrointestinal development of suckling pigs. Oat hulls (OH) were selected as a model feedstuff, rich in cellulose, lignin, and insoluble dietary fibre. Three experimental supplemental diets were formulated: a finely ground, low fibre and nutrient dense diet served as control (CON). For the 2 high fibre diets, 15% heat-treated starch in CON was exchanged with OH, either finely (OH-f) or coarsely ground (OH-c). Litters of 10 primi- and multiparous sows (mean litter size 14.6±0.84) were used. Within a litter, experimental diets were allotted to triplets of 4 piglets. From approximately 12d of age, piglets' individual feed intakes were recorded 2 times per day when separated from their dam for 70min. Piglets could suckle with their dam for the remainder of the day. On d 24 and 25, from the total pool of 120 piglets, seven healthy well-eating piglets per treatment were selected for post-mortem evaluation, resulting in 14 replicates per treatment. Consumption of OH-c and OH-f did not impede clinical health and production performance of piglets. The full stomach weights tended to be greater for OH-c compared to OH-f whereas CON was intermediate (P=0.083). Supplementing OH significantly increased ileal villus height and caecal dry matter concentration (P<0.05). For the colon, OH increased its length, contents weight, short-chain fatty acid concentration and reduced total bacterial count as well as γ-proteobacteria count and proportion (P<0.05). The OH-c treatment specifically increased full gastrointestinal tract weight and caecum contents weight compared to piglets fed CON and OH-f. Furthermore, OH-c reduced colonic crypt depth when compared to OH-f (P=0.018). In conclusion, supplementing OH to a diet for suckling piglets exerted subtle developmental effects on gastrointestinal morphology and colonic microbial community. These effects were largely independent from the particle size of the OH.

Symptomatic Uncomplicated Diverticular Disease (SUDD): Practical Guidance and Challenges for Clinical Management.

Symptomatic Uncomplicated Diverticular Disease (SUDD) is a syndrome within the diverticular disease spectrum, characterized by local abdominal pain with bowel movement changes but without systemic inflammation. This narrative review reports current knowledge, delivers practical guidance, and reveals challenges for the clinical management of SUDD. A broad and common consensus on the definition of SUDD is still needed. However, it is mainly considered a chronic condition that impairs quality of life (QoL) and is characterized by persistent left lower quadrant abdominal pain with bowel movement changes (eg, diarrhea) and low-grade inflammation (eg, elevated calprotectin) but without systemic inflammation. Age, genetic predisposition, obesity, physical inactivity, low-fiber diet, and smoking are considered risk factors. The pathogenesis of SUDD is not entirely clarified. It seems to result from an interaction between fecal microbiota alterations, neuro-immune enteric interactions, and muscular system dysfunction associated with a low-grade and local inflammatory state. At diagnosis, it is essential to assess baseline clinical and Quality of Life (QoL) scores to evaluate treatment efficacy and, ideally, to enroll patients in cohort studies, clinical trials, or registries. SUDD treatments aim to improve symptoms and QoL, prevent recurrence, and avoid disease progression and complications. An overall healthy lifestyle - physical activity and a high-fiber diet, with a focus on whole grains, fruits, and vegetables - is encouraged. Probiotics could effectively reduce symptoms in patients with SUDD, but their utility is missing adequate evidence. Using Rifaximin plus fiber and Mesalazine offers potential in controlling symptoms in patients with SUDD and might prevent acute diverticulitis. Surgery could be considered in patients with medical treatment failure and persistently impaired QoL. Still, studies with well-defined diagnostic criteria for SUDD that evaluate the safety, QoL, effectiveness, and cost-effectiveness of these interventions using standard scores and comparable outcomes are needed.

Exploiting Underutilised crops

Exploiting Underutilised crops

Splanchnic Infusions of Short Chain Fatty Acids Do Not Change Insulin Sensitivity of Pigs

Long-term ingestion of high fiber diets is associated with reduced glucose concentrations during fasting and improved glucose tolerance (KG) in humans. Our objective was to determine if the beneficial effects of fiber were attributable to increased production of short-chain fatty acid (SCFA) in the large intestine. Effects of SCFA on insulin sensitivity (Si), glucose effectiveness (SG), KG and baseline concentrations of glucose, insulin, glucagon and free fatty acids were examined in unfed 20–50 kg pigs (n = 6). Animals randomly received separate portal infusions (0.32 mL·min-1) of saline, acetic, propionic, and butyric acid solutions (0.01 mmol SCFA kg body weight-1·min-1) for 7-d periods. On d 7, somatostatin and tolbutamide modified frequently sampled intravenous glucose tolerance tests were performed. Si and SG were calculated using Bergman's Minimal-Model. KG was determined by regression of log glucose curve versus time. Si, SG and KG values did not differ among the treatments (P > 0.05). Baseline concentrations of glucose, insulin, glucagon and free fatty acids were unaffected by infusion treatment (P > 0.05). Our results suggest that SCFA delivery is not directly responsible for improvements in glucose metabolism observed with long-term ingestion of high fiber diets.

Time-course effects of different fiber-rich ingredients on energy values, microbiota composition and SCFA profile in growing pigs.

This study was to investigate time-course effects of different types of dietary fiber on the energy values, fecal microbiota and short-chain fatty acid (SCFA) concentration in growing pigs. A total of 24 barrows (initial body weight, 19.8±0.5kg) were assigned to 4 dietary treatments based on body weight (BW) in a completely randomized design, including a basal diet (CON) and 3 fiber-rich diets replacing corn, soybean meal and soybean oil in the CON diet with 20% sugar beet pulp (SBP), defatted rice bran (DFRB) or soybean hull (SBH), respectively. Fresh feces were sampled on d 7, 14 and 21, followed by 5d total feces and urine collections. The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7, 14 or 21. However, fiber inclusion decreased the DE and ME of the diet (P<0.05) regardless of the time effect. Principal coordinate analysis (PCoA) revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times (P<0.05) and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point (P<0.05). With adaptation time increased from 7 to 21d, cellulose-degrading bacteria and SCFA-producing bacteria (e.g., Ruminococcaceae _UCG-014, Rikenellaceae _RC9_gut_group and Bifidobacterium) increased in the fiber inclusion diets, and pathogenic genera (e.g., Streptococcus and Selenomonas) were increased in the basal diet (P<0.05). Furthermore, the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet, as reflected by the concentration of propionate, butyrate, isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet (P<0.05). Collectively, our results indicated at least 7d adaptation was required to evaluate the energy values of fiber-rich ingredients, as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet, especially for insoluble dietary fiber.

Gut-Lung Axis

Microbiota and the body's immune system have a two-way interaction that is interconnected. The microbiota plays a role in the formation and maturation of the immune system, on the other hand, the immune system shapes the composition and function of the microbiota. This interaction is important in maintaining the body’s immune system’s homeostasis. The human intestine contains various types of microbes that form the gut microbiota. Various studies have found that changes in the gut microbiota are associated with immunity in distal tissues such as the lung. This gives rise to the concept of a feedback relationship between the gut and lung organs called the gut-lung axis. Through this axis, changes in the composition of the gut microbiota not only cause abnormalities in the gut but also affect microbiota in the lungs and can cause disease. One of the important routes in the transmission of substances from the intestine is through the mesenteric lymphatics. Probiotics can help improve the gut’s defense mechanism. A high-fiber diet can also reduce pathogenic bacteria by increasing levels of short-chain fatty acids. Therefore, a healthy lifestyle is needed to maintain the balance of the microbiota.

Diverticular Disease and Rifaximin: An Evidence-Based Review

There have been considerable advances in the treatment of diverticular disease in recent years. Antibiotics are frequently used to treat symptoms and prevent complications. Rifaximin, a non-absorbable antibiotic, is a common therapeutic choice for symptomatic diverticular disease in various countries, including Italy. Because of its low systemic absorption and high concentration in stools, it is an excellent medicine for targeting the gastrointestinal tract, where it has a beneficial effect in addition to its antibacterial properties. Current evidence shows that cyclical rifaximin usage in conjunction with a high-fiber diet is safe and effective for treating symptomatic uncomplicated diverticular disease, while the cost-effectiveness of long-term treatment is unknown. The use of rifaximin to prevent recurrent diverticulitis is promising, but further studies are needed to confirm its therapeutic benefit. Unfortunately, there is no available evidence on the efficacy of rifaximin treatment for acute uncomplicated diverticulitis.

Effects of hindgut acidosis on inflammation, metabolism, and productivity in lactating dairy cows fed a high-fiber diet

Hindgut acidosis (HGA) may cause or contribute to the inflammatory state of transition dairy cows by compromising the intestinal barrier. Previous experiments isolating the effects of HGA on inflammatory metrics have generated inconsistent results, which may be explained by acclimation to low- versus high-starch diets. Thus, study objectives were to evaluate the effects of HGA in cows acclimated to a high-fiber diet. Ten rumen-cannulated Holstein cows (38 ± 5 kg/d milk yield; 243 ± 62 d in milk; 1.6 ± 1.1 parity; 663 ± 57 kg of body weight) were enrolled in a study with 2 experimental periods (P). Before P1, all cows were acclimated to a high-fiber, low-starch diet (50% neutral detergent fiber, 15% starch) for 17 d. During P1 (4 d), baseline data were collected for use as covariates. During P2 (7 d), cows were assigned to 1 of 2 abomasal infusion treatments: (1) control (CON; 1.5 L of H2O/infusion; n = 4) or (2) starch infused (ST; 1 kg of corn starch + 1.5 L of H2O/infusion; n = 6). All cows were infused with their respective treatments every 6 h daily at 0000, 0600, 1200, and 1800 h, such that ST cows received a total of 4 kg of corn starch/d. Starch infusions successfully induced HGA, as indicated by a marked decrease in fecal pH (1.2 units) relative to CON. However, in contrast to our assumptions, infusing starch had no deleterious effects on milk yield, energy-corrected milk, or voluntary dry matter intake during P2. Milk protein, lactose, their yields, fat yield, and somatic cell score remained unaffected by starch infusions, whereas milk fat content and urea nitrogen were decreased in ST relative to CON (8 and 17%, respectively). Overall, circulating glucose and β-hydroxybutyrate concentrations remained similar between treatments, but starch infusions decreased nonesterified fatty acids on d 3 relative to CON. Blood urea nitrogen decreased throughout P2 in ST (38%) relative to CON. In contrast to our hypothesis, HGA did not alter circulating serum amyloid A or lipopolysaccharide binding protein, nor did it affect rectal temperature. In summary, HGA moderately altered metabolism but did not affect production or elicit an inflammatory response in lactating dairy cows previously acclimated to a high-fiber diet.

High Fiber Diets Slow Bone Turnover in Young Men but Have No Effect on Efficiency of Intestinal Calcium Absorption

Dietary fiber reduces the absorption of dietary calcium from a meal, but its impact on calcium kinetics is unknown. We therefore evaluated the effects of a high fiber diet on calcium balance and kinetics and on calcium-regulating hormones. Seven young men each participated in two 23-d experiments. In the low fiber period the controlled diet provided 6.5 g fiber/d and 530 mg calcium/d. In the high fiber period fiber was increased to 31.3 g/d and calcium to 586 mg/d by substituting high fiber cereal. Measured between d 7 and 12 of each period, the high fiber diet significantly lowered the apparent absorption of calcium (from 60.6 +/- 23.8% to 37.1 +/- 26.5%) and reduced calcium balance, although balance remained positive overall. Fiber had no effect on serum total or ultrafiltrable calcium, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D or parathyroid hormone concentrations measured on d 1, 7, 12 and 20. Calcium kinetics was studied between d 17 and 23 by administering oral 44Ca and intravenous 42Ca to fasting subjects. Fractional absorption of calcium in the fasting state was unaffected by fiber. However, during the high fiber period, subjects had significantly lower bone accretion, resorption and turnover rates, and calcium flow to bone from the exchangeable pool than during the low fiber period. We conclude that the fiber-induced reduction in calcium absorption slowed down bone calcium turnover but did not increase the efficiency of intestinal absorption.

Digestion and utilization of plant-based diets by transgenic pigs secreting β-glucanase, xylanase, and phytase in their salivary glands.

Novel transgenic (TG) pigs co-expressing three microbial enzymes, β-glucanase, xylanase, and phytase, in their salivary glands were previously generated, which exhibited reduced phosphorus and nitrogen emissions and improved growth performances. In the present study, we attempted to explore the age-related change of the TG enzymic activity, the residual activity of the enzymes in the simulated gastrointestinal tract, and the effect of the transgenes on the digestion of nitrogen and phosphorus content in the fiber-rich, plant-based diets. Results showed that all the three enzymes were stably expressed over the growing and finishing periods in the F2 generation TG pigs. In simulated gastric juice, all the three enzymes exhibited excellent gastrointestinal environment adaptability. The apparent total tract digestibility of phosphorus was increased by 69.05% and 499.64%, while fecal phosphate outputs were decreased by 56.66% and 37.32%, in the TG pigs compared with the wild-type littermates fed with low non-starch polysaccharides diets and high fiber diets, respectively. Over half of available phosphorus and water-soluble phosphorus in fecal phosphorus were reduced. We also found the performance of phosphorus, calcium, and nitrogen retention rates were significantly improved, resulting in faster growth performance in TG pigs. The results indicate that TG pigs can effectively digest the high-fiber diets and exhibit good growth performance compared with wild type pigs.

In Vitro Production of Short-Chain Fatty Acids by Bacterial Fermentation of Dietary Fiber Compared with Effects of Those Fibers on Hepatic Sterol Synthesis in Rats

The aim of this study was to determine the effects of fiber feeding on short-chain fatty acid (SCFA) production in laboratory rats and in an in vitro fermentation model using fecal inocula from rats adapted to a high fiber diet. In addition, the effect of fiber intake on endogenous sterol synthesis was evaluated. Twenty male Sprague-Dawley rats were divided into four groups and fed a control or 30% fiber diet (cellulose, pectin or pea fiber) for 4 wk. In vitro fermentation was compared with measurements of cecal SCFA content of fiber-adapted rats. Sterol synthesis in isolated hepatocytes was determined in groups of five to seven rats fed 15% dietary fiber for 4 wk. Cellulose was poorly fermented in both the in vitro and in vivo experiments. Pectin fermentation produced high levels of propionate, whereas pea fiber was associated with notable butyrate production. Adaptation to pectin produced seven times more SCFA in rat cecal contents (515 +/- 78 mumol) in comparison to a fiber-free diet (70.6 +/- 4.9 mumol), with similar results observed in vitro. Sterol synthesis in hepatocytes of rats fed pectin was significantly greater than in those of control or cellulose-fed rats. Despite significantly higher rates of SCFA production in pectin-fed rats, cholesterol synthesis was not inhibited, suggesting that SCFA are not the cholesterol-lowering factor of highly fermentable fiber sources.

Fasting Protocols Do Not Improve Intestinal Architecture and Immune Parameters in C57BL/6 Male Mice Fed a High Fat Diet.

The intestinal ecosystem, including epithelium, immune cells, and microbiota, are influenced by diet and timing of food consumption. The purpose of this study was to evaluate various dietary protocols after ad libitum high fat diet (HFD) consumption on intestinal morphology and mucosal immunity. C57BL/6 male mice were fed a 45% high fat diet (HFD) for 6 weeks and then randomized to the following protocols; (1) chow, (2) a purified high fiber diet known as the Daniel Fast (DF), HFD consumed (3) ad libitum or in a restricted manner; (4) caloric-restricted, (5) time-restricted (six hours of fasting in each 24 h), or (6) alternate-day fasting (24 h fasting every other day). Intestinal morphology and gut-associated immune parameters were investigated after 2 months on respective protocols. Consuming a HFD resulted in shortening of the intestine and reduction in villi and crypt size. Fasting, while consuming the HFD, did not restore these parameters to the extent seen with the chow and DF diet. Goblet cell number and regulatory T cells had improved recovery with high fiber diets, not seen with the HFD irrespective of fasting. Nutritional content is a critical determinant of intestinal parameters associated with gut health.

Ultra-sensitive isotope probing to quantify activity and substrate assimilation in microbiomes

BackgroundStable isotope probing (SIP) approaches are a critical tool in microbiome research to determine associations between species and substrates, as well as the activity of species. The application of these approaches ranges from studying microbial communities important for global biogeochemical cycling to host-microbiota interactions in the intestinal tract. Current SIP approaches, such as DNA-SIP or nanoSIMS allow to analyze incorporation of stable isotopes with high coverage of taxa in a community and at the single cell level, respectively, however they are limited in terms of sensitivity, resolution or throughput.ResultsHere, we present an ultra-sensitive, high-throughput protein-based stable isotope probing approach (Protein-SIP), which cuts cost for labeled substrates by 50–99% as compared to other SIP and Protein-SIP approaches and thus enables isotope labeling experiments on much larger scales and with higher replication. The approach allows for the determination of isotope incorporation into microbiome members with species level resolution using standard metaproteomics liquid chromatography-tandem mass spectrometry (LC–MS/MS) measurements. At the core of the approach are new algorithms to analyze the data, which have been implemented in an open-source software (https://sourceforge.net/projects/calis-p/). We demonstrate sensitivity, precision and accuracy using bacterial cultures and mock communities with different labeling schemes. Furthermore, we benchmark our approach against two existing Protein-SIP approaches and show that in the low labeling range used our approach is the most sensitive and accurate. Finally, we measure translational activity using 18O heavy water labeling in a 63-species community derived from human fecal samples grown on media simulating two different diets. Activity could be quantified on average for 27 species per sample, with 9 species showing significantly higher activity on a high protein diet, as compared to a high fiber diet. Surprisingly, among the species with increased activity on high protein were several Bacteroides species known as fiber consumers. Apparently, protein supply is a critical consideration when assessing growth of intestinal microbes on fiber, including fiber-based prebiotics.ConclusionsWe demonstrate that our Protein-SIP approach allows for the ultra-sensitive (0.01 to 10% label) detection of stable isotopes of elements found in proteins, using standard metaproteomics data.

Current nutritional guidelines in terms of the effect on gut microbiota and human health considering the WHO and FAO recommendations

The purpose of this paper is to evaluate current nutritional guidelines of modern diets based on medical and nutrition facts and their effect on gut microbiota and health, considering current recommendations of world authorities such as FAO and WHO. For this purpose, the first part is devoted to the impact of microbiota on human health, and special attention is committed to the effect of fibre on gut microbiota. The second part is dedicated to the fundamental division of diets and the evaluation of concrete nutritional guidelines of modern diets into microbiota and health, followed by the recommendations of global authorities. Modern diets include diets from the point of view of medical science (e.g. Mediterranean), promoted by nutritionists and authorities (e.g. Nordic) and by social trends (e.g. vegan). The evaluation summarises that high-fibre diets have tremendous benefits on human health. Diets with fresh, local and naturally fermented food positively impact the gut microbiota, hence human health (agrarian diets). The results of the review show that the nutritional guidelines associated with the lowest mortality are the Mediterranean with the Atlantic or Nordic diet, which is in line with the recommendation of the world authorities (FAO, WHO, UN). The low-fibre western diet with highly processed foods with no or very low levels of live bacteria appears to be high-risk in terms of preventing civilisation diseases with a negative impact on gut microbiota, which is in line with current FAO and WHO guidelines.

Eficacia de la dieta alta en fibra en la mejora del estreñimiento en pacientes con disinergia defecatoria en tratamiento con biofeedback anorrectal. Ensayo clínico exploratorio, aleatorizado

IntroductionFiber is the initial treatment in chronic functional constipation. However, its role in the group of patients with defecatory dyssynergy is not well established. The objective of the study is to evaluate the efficacy and safety of a high fiber diet in patients with defecatory dyssynergy in the treatment with anorectal biofeedback. Patients and methodsAn exploratory, randomized (1:1), double-blind, controlled «add-on» clinical trial was carried out in a reference center in Spain in patients with functional constipation and defecatory dyssynergy according to the ROMEIV criteria. Control group: treatment with biofeedback and low-fiber diet (15-20g/day). Experimental group: treatment with biofeedback and high fiber diet (25-30g/day). Analyzed: responder (primary endpoint), patient whose defecatory dyssynergy had been corrected (>20% reduction in anal pressure during the defecation maneuver and normal balloon expulsion test); anorectal parameters (anal relaxation, reduced straining); safety (abdominal symptoms: flatulence, pain, borborygmus, bloating). ResultsA total of 44 patients were randomized: 22 per group. The percentage of responders was 75% (15/20; 95%CI: 53 89%) control group and 70% (14/20; 95%CI: 48-85%) experimental group, P=.225. Differences in favor of the control group were only observed in abdominal symptoms: flatulence (P=.028), abdominal distension (P=.041) and digestive comfort (P=.043). ConclusionsIn patients with defecatory dyssynergy, a high-fiber diet not only does not improve the efficacy of anorectal biofeedback but is associated with a loss of improvement in abdominal symptoms.