Search Results (395)

Antibiotics may be used for gastrointestinal enteropathies but research has demonstrated significant microbiota dysmetabolism, fermentation pattern alterations, and prolonged dysbiosis following treatment. The objective of this study was to determine how dietary fiber or fecal microbial transplant (FMT) treatments impacted the fecal characteristics, metabolite concentrations, and microbiota populations of cats treated with metronidazole. Twenty-five healthy adult cats (6.75 ± 1.20 yr) were fed a commercial kibble diet for 2 wk, administered metronidazole (20 mg/kg BW BID) for 2 wk, then monitored for 4 wk. Cats were allotted to one of three interventions (diet, diet + beet pulp, diet + FMT) for 1 wk, interventions ceased, then recovery was monitored for 4 wk. Fresh fecal samples were collected at the end of each phase and at the mid-points of recovery. As anticipated, metronidazole increased fecal scores and moisture (p < 0.05), reduced fecal bacterial alpha diversity (p < 0.0001), and reduced fecal metabolite concentrations. Few treatment effects were detected, with antibiotic recovery contributing to many of the results observed. Dysbiosis was persistent throughout the study, with 4/25 cats still demonstrating mild dysbiosis after 9 wk. Overall, dietary or FMT treatments may aid in accelerated antibiotic recovery in cats but further research is needed to refine treatments for greater efficacy. Full article

Short-chain fatty acids (SCFAs) are metabolites derived from the fermentation of dietary fibre by gut bacteria. SCFAs function as essential regulators of host-microbiome interactions by participating in numerous physiological and pathological processes within the gastrointestinal (GI) tract. In recent years, the depletion of SCFAs has been increasingly linked to the pathogenesis of GI diseases. In this review, we summarize the current understanding of the therapeutic mechanisms of SCFAs in GI diseases, including inflammatory bowel disease, irritable bowel syndrome, metabolic dysfunction-associated steatotic liver disease, and acute pancreatitis. We next highlight potential therapeutic approaches that increase the endogenous production of SCFAs, including prebiotics, probiotics, and fecal microbiota transplantation. We conclude that, although SCFAs are promising therapeutic agents, further research is necessary due to variability in treatment efficacy, inconsistent clinical outcomes, and a limited understanding of SCFAs’ mechanisms of action. Full article

This study evaluated the effects of early-life creep feeding with a high-protein, high-energy diet on growth performance, ruminal fermentation, and gut microbiota in Hanwoo calves (n = 10). Calves were assigned to control or treatment groups from birth to 6 months of age. No significant differences were observed in body weight, average daily gain (ADG), or feed conversion ratio (FCR), but ADG and dry matter intake (DMI) tended to be higher in the treatment group. Ruminal pH, NH₃-N, and volatile fatty acid (VFA) concentrations showed no significant differences. Fecal VFA profiles exhibited numerical trends suggesting higher propionate at 3 months and lower acetate, butyrate, and total VFA at 6 months in the treatment group, potentially reflecting altered substrate availability or absorption capacity, though these mechanisms were not directly measured. Microbiota analysis indicated stable ruminal alpha diversity, with numerical increases in fecal Bacteroidetes and genera such as Fournierella and Flavonifractor in the treatment group. These results suggest that early creep feeding with high-nutrition diets can support intake and promote potential shifts in hindgut microbiota composition without compromising overall microbial stability. Further research with larger sample sizes is needed to confirm these trends and assess long-term impacts on calf health and productivity. Full article

Odors from pet cats can negatively affect the quality of life of cat owners. The diverse bioactive compounds in plant extracts make them a promising candidate for effective odor reduction. This study evaluated twelve plant extracts for deodorizing efficacy via in vitro fermentation tests. Rosemary extract and licorice extract exhibited better deodorizing effects, with fractions of rosemary extract below 100 Da demonstrating the most effective deodorizing performance. Based on these findings, subsequent feeding trials were conducted using rosemary extract and its fractions below 100 Da. In the feeding trial, adult British Shorthair cats were divided into three groups (Control Check, RE, and RE100) and housed in a controlled-environment respiration chamber for 30 days. Measurements included odor emissions, fecal and blood physicochemical parameters, immune parameters, microbiota composition based on 16S rRNA sequencing, and metabolome analysis. The results of the feeding trial indicated that rosemary extract significantly reduced ammonia and hydrogen sulfide emissions (46.84%, 41.64%), while fractions below 100 Da of rosemary extract achieved even greater reductions (55.62%, 53.87%). Rosemary extract regulated the intestinal microbial community, significantly increasing the relative abundance of the intestinal probiotic Bifidobacterium (p < 0.05) and reducing the population of sulfate-reducing bacteria (p < 0.05). It also significantly reduced urease and uricase activities (p < 0.05) to reduce ammonia production and inhibited the degradation of sulfur-containing proteins and sulfate reduction to reduce hydrogen sulfide emissions. Furthermore, rosemary extract significantly enhanced the immune function of British Shorthair cats (p < 0.05). This study suggests that rosemary extract, particularly its fractions below 100 Da, is a highly promising pet deodorizer. Full article

Background: Constipation is a common gastrointestinal disorder with a significant impact on quality of life. Methods: Constipation was induced in male ICR mice via 25% cotrimoxazole gavage (20 mL/kg/day for 7 days). Mice were divided into prevention (pre-MBSFL), treatment (MBSFL), and control groups. MBSFL was prepared by fermenting mung bean starch with Lactobacillus plantarum (1:3 w/v ratio, 37 °C for 48 h), and administered via daily oral gavage (250 mg/kg bw) for 14 days. Fecal parameters (water content and first black stool latency), gastrointestinal motility (gastric emptying and small intestinal propulsion), serum biomarkers (NO, VIP, SP, and 5-HT), and intestinal gene expression (5HTR₄, SERT, and MAO_A) were analyzed. Results: MBSFL intervention restored fecal water content by 38%, reduced first black stool latency from 6.2 h to 3.1 h, and improved small intestinal propulsion by 64%. Additionally, it downregulated serum NO (25%) and VIP (32%) while upregulating SP (49%) and 5-HT (78%) levels. Intestinal 5HTR4 and SERT expression increased by 78% and 71%, respectively, with MAOA suppression (25%). Microbial analysis revealed a 140% increase in Dubosiella and 49% in Lactobacillus abundance, alongside a 62% reduction in Mucispirillum. MBSFL contained polysaccharides (12.3% w/w) and organic acids, including hydroxy butyric acid (4.2 mg/mL). Conclusions: MBSFL alleviates constipation through dual mechanisms: modulating 5-HT pathway activity and restoring gut microbiota homeostasis. Full article

The discovery that human beings may endogenously produce ethanol is not new and dates back at the end of the 19th century; recently, however, it has become clear that through the proliferation of gut microorganisms that produce ethanol from sugars or other substrates, blood alcohol level may be greater than 0, despite Homo sapiens sapiens lacking the enzymatic pathways to produce it. Very rarely this can lead to symptoms and/or to a disease, named gut fermentation syndrome or auto-brewery syndrome (ABS). The list of microorganisms (mostly bacteria and fungi) is very long and contains almost 100 different strains, and many metabolic pathways are involved. Endogenous ethanol production is a neglected entity, but it may be suspected in patients in whom ethanol consumption may be firmly excluded. Nevertheless, due to the growing prevalence of NAFLD (now renamed as MAFLD) worldwide, an ethanol-producing microorganism responsible for endogenous ethanol production such as Klebsiella pneumoniae or Saccharomices cerevisiae is increasingly sought in NAFLD patients, or in patients with metabolic diseases such as diabetes mellitus, obesity, or metabolic syndrome, at least in selected instances. In the absence of standard diagnostic and therapeutic guidelines, ABS requires a detailed patient history, including dietary habits, alcohol consumption, and gastrointestinal symptoms, and a comprehensive physical examination to detect unexplained ethanol intoxication. It has been proposed to start the diagnostic protocol with a standardized carbohydrate challenge test, followed, if positive, by the use of antifungal agents or antibiotics; indeed, fecal microbiota transplantation might be the only way to cure a patient with refractory ABS. Scientific societies should produce internationally agreed recommendations for ABS and other conditions linked to excessive endogenous ethanol production. Full article

Our previous study has shown that supplementation of 0.50% benzoic acid (BA) increased growth performance, promoted rumen fermentation, and improved the composition and function of rumen microbiota. This research was designed to conduct a deeper exploration of the impacts of dietary supplementation with BA on the apparent digestibility of nutrients and the composition of rectal microbiota in weaned Holstein dairy calves. Sixteen Holstein heifer calves with similar body weights (91.2 ± 0.7 kg) were selected and randomly allocated into two groups, each comprising eight calves. Calves in the control group (CON group) were fed with a basal diet, while those in the benzoic acid group (BA group) were fed with the basal diet supplemented with 0.50% benzoic acid (on a dry matter basis). The experimental period started at 60 days of age and ended at 102 days of age, lasting for a total of 42 days. The calves were weaned at 60 days of age, with a transition period of 7 days. Feed samples were collected every two weeks, fecal samples were collected from 99 to 101 days of age, and blood samples were collected at 102 days of age. The results showed that supplementation with BA did not influence the digestibility of dry matter, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, calcium, and phosphorus between the two groups. Compared with the CON group, BA supplementation tended to decrease the total cholesterol (TC) in the serum of the calves (p = 0.067). Supplementation with BA increased the relative abundances of the two beneficial bacteria, Bifidobacterium and Bifidobacterium pseudolongum (p < 0.05, LDA > 2), but decreased that of the harmful bacterium, Clostridium sensu stricto 1, in the rectum of dairy calves. The microbial functional prediction revealed that the fecal microbial metabolism involved in primary bile acid biosynthesis was higher in the calves from the BA group. In conclusion, the present study demonstrated that adding 0.50% BA to the diet did not influence the apparent nutrient digestibility, but improved rectal microbiota health, which finally promoted the growth performance in weaned Holstein dairy calves. Full article

The gut microbiota, dominated by bacteria from the Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria phyla, plays an essential role in fermenting indigestible carbohydrates, regulating metabolism, synthesizing vitamins, and maintaining immune functions and intestinal barrier integrity. Dysbiosis is associated with obesity development. Shifts in the ratio of Firmicutes to Bacteroidetes, particularly an increase in Firmicutes, may promote enhanced energy storage, appetite dysregulation, and increased inflammatory processes linked to insulin resistance and other metabolic disorders. The purpose of this literature review is to summarize the current state of knowledge on the relationship between the development and treatment of obesity and overweight and the gut microbiota. Current evidence suggests that probiotics, prebiotics, synbiotics, and fecal microbiota transplantation (FMT) can influence gut microbiota composition and metabolic parameters, including body weight and BMI. The most promising effects are observed with probiotic supplementation, particularly when combined with prebiotics, although efficacy depends on strain type, dose, and duration. Despite encouraging preclinical findings, FMT has shown limited and inconsistent results in human studies. Diet and physical activity are key modulators of the gut microbiota. Fiber, plant proteins, and omega-3 fatty acids support beneficial bacteria, while diets low in fiber and high in saturated fats promote dysbiosis. Aerobic exercise increases microbial diversity and supports growth of favorable bacterial strains. While microbiota changes do not always lead to immediate weight loss, modulating gut microbiota represents an important aspect of obesity prevention and treatment strategies. Further research is necessary to better understand the mechanisms and therapeutic potential of these interventions. Full article

The objective of this study was to evaluate the effects of various feed additives on odor emissions, gut health, and stress responses in laying hens fed low-protein diets. Four commercially available functional feed additives (Bacillus subtilis, protease, saponin, and thyme-based essential oil) were selected for this study. A total of 288 Hy-Line brown laying hens aged 49 weeks were randomly fed on one of six experiment diets: a 16% standard crude protein diet, a 12% low-crude-protein (LCP) diet, and LCP diets supplemented with Bacillus-based probiotic, protease, saponin, or thyme-based essential oils prepared for 8 weeks. Each treatment had eight replicates with six birds per replicate. Lowering crude protein levels affected the laying performance, nitrogen balance, odor production (i.e., ammonia), and nutrient digestibility but did not alter eggshell quality or fecal short-chain fatty acids. Dietary additives added into the LCP diet did not affect the laying performance, egg qualities, and nitrogen balance but increased crude ash digestibility compared with the LCP-diet-fed laying hens. Branched-chain fatty acids tended to be higher in all laying hens fed low-CP diets, irrespective of feed additives. Notably, low vs. standard protein diets tended to increase yolk corticosterone levels, which is an indicator of stress responses in chickens. This low-CP-mediated increase in yolk corticosterone was partially decreased by 20.8–48.6% on average, depending on the additives used. Our study suggests that low-protein diets could effectively lower nitrogen excretion and odor emissions. However, adding dietary additives into low-protein diets has minimal effects on low-CP-diet-fed laying hens, which needs further studies to clarify the role of low-crude-protein diets and dietary additives in modulating hindgut fermentation via shaping the gut microbiota and stress responses of laying hens. Full article

Chitosan and technical cashew nutshell liquid (CNSLt) have emerged as promising natural compounds due to their antimicrobial, immunomodulatory, and fermentation-modulating properties. This study aimed to evaluate the inclusion of chitosan and CNSLt as potential substitutes for the ionophore monensin on feed intake, ruminal fermentation, nitrogen balance, and microbial protein synthesis in steers. Five crossbred steers (Bos taurus), 18 months old with an average body weight of approximately 350 kg and fitted with permanent ruminal cannulas, were assigned to a 5 × 5 Latin square design. The experimental diets consisted of: (1) control (CON), (2) monensin (MON; 25 mg/kg of dry matter [DM]), (3) chitosan (CHI; ≥850 g/kg deacetylation degree, 375 mg/kg DM), (4) CNSLt (500 mg/kg DM), and (5) CNSLt + CHI (500 + 375 mg/kg DM). Supplementation with CHI or CNSLt + CHI reduced the intake of dry matter, crude protein, and neutral detergent fiber. Additionally, fecal excretion of whole corn kernels increased in these treatments. Ruminal fermentation parameters were affected, with the CNSLt + CHI treatment promoting higher molar proportions of propionate and acetate, along with reduced estimated methane emissions. However, purine derivatives, microbial protein synthesis, and nitrogen balance were not significantly affected by any of the treatments. These results suggest that CNSLt and CHI, particularly when combined, may serve as effective natural alternatives to monensin in high-grain diets for ruminants. Full article

Background: Colorectal cancer (CRC) is among the leading causes of cancer-related mortality worldwide, with increasing attention being paid to modifiable dietary factors in its prevention. Hazelnut (Corylus avellana L.) represent a nutrient-dense food rich in unsaturated fats, polyphenols, fiber, and phytosterols, with potential anticarcinogenic properties. This systematic review aimed to evaluate the role of hazelnut consumption in the prevention and modulation of CRC risk, with specific focus on experimental, mechanistic, and preclinical evidence. Methods: Following PRISMA guidelines, a systematic search was conducted in PubMed, Google Scholar, and the Cochrane Library for articles published from 2015 onward. Eligible studies included original in vitro and in vivo models, as well as observational studies, evaluating hazelnut or hazelnut-derived products in relation to CRC-related biological, metabolic, or clinical outcomes. Data extraction focused on bioactive composition, experimental models, molecular pathways, and fecal/metabolic markers of carcinogenesis. Results: A total of 11 studies were included after screening 24 records: 8 in vitro investigations, 2 in vivo animal experiments, and 1 epidemiological study. In vitro studies showed that hazelnut derivatives—including fermented hazelnuts and oil-based extracts—exert antiproliferative effects via BAX/BCL-2 modulation, increased caspase-3 activity, and oxidative stress reduction. In vivo studies confirmed improved lipid metabolism, modulation of bile acid composition (notably reduced lithocholic/deoxycholic acid ratio), and enhanced antioxidant defenses. FIBEROX^®, a hazelnut skin extract enriched in dietary fiber, demonstrated promising effects on gut microbiota and bile acid detoxification. Conclusions: Hazelnut and their bioactive compounds may aid CRC prevention through multiple molecular and metabolic pathways. Further human studies are needed to confirm these effects and support dietary recommendations. Full article

The increasing prevalence of non-communicable diseases (NCDs) is strongly associated with gut microbiota (GM) imbalances and reduced short-chain fatty acid (SCFA) production, primarily driven by poor diet and microbial dysbiosis. Since SCFAs are crucial for gut health, immune regulation, and inflammation control, restoring their levels is a key therapeutic target. SCFA-acylated naringin derivatives offer a novel approach by enhancing SCFA delivery and modulating GM composition. In this study, we investigated the effects of naringin acetate and naringin propionate on SCFA production using a 24 h short-term in vitro batch fecal fermentation model with microbiota from two donors. Naringin propionate and naringin plus free propionate significantly increased propionate levels by 0.74 mM and 0.75 mM, respectively (p < 0.0001), while naringin acetate induced a smaller increase of 0.26 mM. Donor-specific reflected differences in microbial communities, yet SCFA enhancement was observed across samples. Additionally, naringin treatments stimulated the growth of beneficial polyphenol-metabolizing bacteria, including Bacteroides, Streptococcus, and Eubacterium siraeum. The strong effect of naringin propionate suggests a sustained SCFA release mediated by microbial enzymes. These preliminary results highlight the potential of SCFA-acylated flavonoids as functional dietary components to increase SCFA bioavailability and support gut health, particularly from citrus-derived co-products. Full article

Tetraselmis chuii is a microalga commercialized because of its richness in health-beneficial molecules. Previous studies have profusely demonstrated the biological properties of compounds isolated from T. chuii, but data are not yet available on the impact that gastrointestinal digestion could exert. This article describes the passage of T. chuii through the gastrointestinal tract, combining the INFOGEST procedure and in vitro colonic fermentation to examine potential effects on the human colonic microflora composition and its metabolic activity. Microbial plate counting was conducted to determine the different groups of microorganisms. Amplification of the 16S ribosomal RNA gene was performed via polymerase chain reaction to examine in detail the main genera of bacteria, and its metabolic activity was evaluated by measuring of short-chain fatty acids (SCFAs) by gas chromatography. The presence of T. chuii modified the fecal microbiota. Although the evolution of lactic acid bacteria and Enterococcus spp. content during 72 h showed that the use of T. chuii, compared to fructopolysaccharides such as inulin, would not provide nutritional advantages, the microalgae extract contributed to a significant decrease in Clostridium, Staphylococcus, and Enterobacteriaceae. Furthermore, T. chuii increased the relative abundance of Akkermansia and Butyricimonas, genera considered highly beneficial. In correlation with the presence of these microorganisms, the results show that the presence of T. chuii favored the release of SCFA, such as acetic (20 mM), propionic (>5 mM), isovaleric (0.3 mM), isobutyric (0.15 mM), and, mainly, butyric (>2 mM), after 72 h colonic fermentation, being indicators of gut health. These findings suggest that T. chuii has potential as a functional ingredient for promoting health through its modulatory effects on the intestinal microbiota. Full article

The production of novel oligosaccharides with potential prebiotic effects is of interest to expand the current market and explore the effectiveness of new functional carbohydrate forms. The utilization of glucansucrases is a cost-effective and environmentally friendly biotechnological strategy for producing novel gluco-oligosaccharides through acceptor reactions. In this study, an active glucansucrase (GS53) was used to produce gluco-oligosaccharides via its acceptor reactions with glucose, maltose, and maltotriose, and these oligosaccharides were tested in terms of structure and their gut microbiome modulatory effects. The formations of oligosaccharides were monitored by TLC analysis, and GS53 was active for the three acceptors but not for the other sugars tested. The structural characterization of the gluco-oligosaccharides by ¹H NMR analysis revealed the glycosylation of each acceptor with α-(1 → 3) and α-(1 → 6) linkages, whereas LC-MS analysis demonstrated the formations of DP 8, DP 7, and DP 6 oligosaccharides with acceptors maltose, maltotriose, and glucose, respectively. In vitro fecal fermentation analysis, in which microbial short-chain fatty acids (SCFAs) and microbial compositional changes were assessed using gas chromatography and 16S rRNA sequencing, respectively, demonstrated that the gluco-oligosaccharides formed SCFAs—particularly propionate and butyrate—at levels comparable to those observed with inulin, a well-established prebiotic. Additionally, the gluco-oligosaccharides were found to promote the growth of Bifidobacterium adolescentis and Blautia OTUs, which are known to have important physiological functions beneficial to human health. Overall, these results demonstrate that gluco-oligosaccharides synthesized using GS53 through acceptor reactions exhibit prebiotic potentials and could be utilized in the future as dietary supplements as well as in the development of functional foods targeting colonic health. Full article

Dietary nutrient digestion and utilization patterns influence pig performance and intestinal health. This study aimed to evaluate the effects of protein digestion and fiber fermentation speed among different feed ingredients on growth performance and fecal short-chain fatty acid (SCFA) concentrations in weaned pigs. A total of 192 weaned pigs (Duroc × Landrace × Yorkshire [6.87 ± 0.14 kg]) were selected and randomly divided into four dietary groups: fast-digesting protein with fast-fermenting fiber, fast-digesting protein with slow-fermenting fiber, slow-digesting protein with fast-fermenting fiber, and slow-digesting protein with slow-fermenting fiber. The results showed that cottonseed and wheat protein powders exhibited faster protein digestion than potato protein powder (p < 0.05). In vitro microbial fermentation of hawthorn powder and orange pomace resulted in greater and faster gas production and SCFA concentrations than sugarcane bagasse (p < 0.05). Orange pomace increased the abundance of Klebsiella and Escherichia–Shigella, whereas sugarcane bagasse increased the abundance of Rikenellaceae_RC9_gut_group and norank_f__Muribaculaceae. In addition, the fast-fermentation fiber tended to increase the daily weight gain and feed intake of piglets (p < 0.10), and the slow-fermentation fiber significantly reduced diarrhea incidence in pigs (p < 0.05). Fast fermentation increased acetate and valerate concentrations, and slow-digestion protein increased branched-chain SCFA and valerate contents (p < 0.05). In conclusion, there were large variations in protein digestion and fiber fermentation speed among the different common feed ingredients. Dietary protein digestion and fiber fermentation speed would affect growth performance and diarrhea incidence in weaned pigs. Full article