Fermented milk containing Lacticaseibacillus paracasei strain Shirota (LcS) has been shown to improve stool consistency in various countries; however, its effect on hard or lumpy stools (HLS) in the Vietnamese population remains unclear. We investigated the effects of LcS-fermented milk on constipated Vietnamese adults with a high prevalence of HLS. In a single-centre, open-label trial, 51 participants with HLS were randomised to receive one bottle per day of fermented milk containing ≥6.5× 109 cfu of LcS for 4 weeks (probiotic group) or no intervention (control group), followed by a 2-week washout. The primary endpoint was the proportion of participants with HLS (Bristol Stool Form Scale score of 1 or 2) in ≥25% of bowel movements over 4 weeks. Secondary endpoints included total stool frequency, HLS frequency, ideal stool form, and defecation-related symptoms - all recorded in daily diaries. The Chinese Constipation Questionnaire (CCQ) and gut microbiota composition (16S rRNA sequencing) were assessed every 2 weeks. During the intervention, the probiotic group had a significantly lower proportion of participants with HLS in ≥25% of bowel movements compared to controls (odds ratio: 0.00; 95% confidence interval: 0.00-0.16; P = 0.005). The probiotic group also showed increased total stool frequency ( P = 0.001), reduced HLS frequency ( P = 0.035), and fewer participants with CCQ scores ≥5 indicating constipation ( P < 0.001) at 4 weeks. Gut microbiota beta-diversity differed between groups after 2 weeks ( P = 0.031), with reductions in Peptococcaceae, Clostridium_methylpentosum_group, and Clostridia (unclassified at the order level), followed by increases in Lachnospiraceae_UCG-004 at 4 weeks and Lachnospiraceae_ND3007_group post-follow-up ( P < 0.050), suggesting microbial changes linked to constipation improvement. No serious adverse events related to the intervention were observed. These findings support daily LcS-fermented milk as a dietary strategy in Vietnam to manage constipation via gut microbiota modulation. The study was registered at ClinicalTrials.gov (ID: NCT05982743).

Obesity is a growing public health concern in the Middle East and North Africa (MENA) region, yet limited research has explored how gut microbiota varies between Arab populations. This study compared the gut microbiota composition and diversity of Emirati and Lebanese adults with obesity and assessed the role of age and nationality in shaping microbial variation. A total of 43 Emirati and 30 Lebanese individuals with obesity (body mass index (BMI) ≥35kg/m2) were recruited. Participants provided anthropometric and biochemical data, dietary records, and stool samples for 16S rRNA sequencing. The analysis revealed significantly higher BMI, weight, and fat mass in Emirati participants, while Lebanese individuals reported higher fibre intake. Taxonomic profiling showed higher relative abundances of Pseudomonadota, Mycoplasmatota, Cyanobacteriota, and Lentisphaerota in the Lebanese group, whereas Bacteroidota was more abundant among Emiratis. Lebanese participants also exhibited significantly greater microbial alpha-diversity. Beta-diversity analysis confirmed clear distinctions in microbial community structure between the two groups. Linear Discriminant Analysis Effect Size (LefSe) (LDA score >10log2) and regression models ( P < 0.05) identified specific bacterial genera associated with nationality, although these associations were attenuated after adjusting for age. These findings suggest that gut microbiota in Arab populations is influenced by demographic, dietary, and environmental factors, emphasising the need for culturally tailored microbiota-based strategies to manage obesity and related metabolic conditions.

We investigated the therapeutic potential of Lactobacillus salivarius in colitis mice, and the mice were randomly allocated into three groups with each consisting of 10 mice (n= 10): a control group (CSG), a DSS-induced colitis model group (DSG), and a L. salivarius intervention group (LSG). The intervention group received daily oral administration of L. salivarius for seven consecutive days. Compared to the DSS model group, mice receiving L. salivarius exhibited significantly reduced weight loss, lower DAI scores, lessened colon shortening, and improved histopathological profiles, indicating a substantial reduction in inflammatory damage. Additionally, ITS sequencing revealed that L. salivarius significantly influenced the composition of the intestinal fungal community, decreasing the abundance of pathogenic fungi, such as Candida species, by approximately 40%, and restoring fungal homeostasis by reducing the Basidiomycota/Ascomycota ratio. Moreover, L. salivarius effectively alleviated DSS-induced oxidative stress by lowering serum MDA levels while enhancing the activity of SOD and GSH-Px. Furthermore, the probiotic intervention resulted in 30-40% reduction in pro-inflammatory factors (TNF-α, IL-6, and IL-1β) and an increase in the anti-inflammatory factor IL-10 levels, suggesting a pronounced anti-inflammatory effect. In conclusion, L. salivarius exerts significant protective effects against DSS-induced colitis by modulating the gut fungal community, mitigating oxidative stress, and suppressing inflammatory responses. This study is novel in that few probiotic studies have investigated the impact of L. salivarius on gut fungi in DSS-induced colitis. These findings highlight its potential as a therapeutic candidate for managing inflammatory bowel disease.

Irritable bowel syndrome (IBS) is faced by gastroenterologists daily, and probiotics are a potential therapeutic tool; however, there are no strain recommendations. This multicenter, real-world, single-arm, open-label study aims to assess a novel probiotic mixture's effectiveness, safety, and patient satisfaction in patients with IBS. This study was conducted by 52 Italian gastroenterologists across 16 of the 21 Italian regions who enrolled patients with IBS (n= 1,098). Throughout the 8-week treatment (T1) period with a probiotic mixture (Lactobacillus paracasei 101/37 LMG P-17504, Lactobacillus plantarum 14D CECT 4528, Bifidobacterium breve Bbr8 LMG P-17501, Bifidobacterium breve BL10 LMG P-17500, and Bifidobacterium animalis ssp. lactis Bi1 LMG P-17502), participants completed a questionnaire to evaluate IBS symptoms at baseline, at the end of treatment, and after one-month follow-up (T2). The primary outcome was the progress of abdominal pain and bloating according with a 5-point Likert scale, (0 absence and 5 highly intense symptoms) and treatment success was defined as a change towards categories of lower IBS severity for abdominal pain and/or bloating. Treatment success for abdominal pain and bloating was achieved in 73% and 81.9% at T1 and 68% and 73.1% at T2, respectively. The probiotic was associated with significantly reducing abdominal pain and bloating at T1 and T2 (P< 0.001). Patients with regular bowel movements increased to 68.5% at T1 and 68.7% at T2, respectively (P< 0.001). Patients reporting that IBS did not affect their daily life increased from 1.8% at entry to 22.7% at T1 and 41.6% at T2 (P< 0.001). This real-world, single-arm, open-label study showed that an 8-week treatment with a novel probiotic mixture is effective, safe, well tolerated, and can improve patients' social lives during and after treatment. Future randomised placebo-controlled studies are necessary to validate these findings. The trial is registered at www.ClinicalTrials.gov (NCT06610149).

Abnormal colonisation of the ileal mucosa by adherent-invasive Escherichia coli (AIEC) is a key feature of Crohn's disease. To date, no curative treatment for this disease exists, highlighting the need to develop new therapies targeting the origin of the inflammation, in particular the intestinal microbiota and more specifically AIEC. This study investigated the anti-virulence properties of 17 bacterial strains (lactobacilli and bifidobacteria) and three plant extracts (walnut and green tea leaves and liquorice roots) against AIEC. In vitro, six lactobacilli strains and one bifidobacterium strain reduced AIEC LF82 adhesion to Caco-2/TC7 cells and/or suppressed IL-8 secretion induced by AIEC. Although plant extracts did not prevent adhesion or inflammation, they inhibited AIEC growth. In a murine model of dextran sulfate sodium-induced colitis exacerbated by LF82 infection, two Lacticaseibacillus strains, one Bifidobacterium strain, and walnut and green tea extracts efficiently alleviated colitis and reduced faecal lipocalin-2 levels. For the green tea extract and one Lacticaseibacillus strain, beneficial effects were correlated with a decreased number of AIEC associated with the colonic mucosa. Building on these findings, bacteria and plant extract combinations were tested in the same model. A formulation combining two Lacticaseibacillus strains (Lbs. casei and Lbs. rhamnosus) with the walnut extract demonstrated the greatest efficacy, markedly reducing colitis score and preserving intestinal mucosa integrity. While untreated mice remained heavily colonised, the combination promoted AIEC elimination from the gut of half the mice, contributing to the alleviation of colitis symptoms. These results highlight the ability of combinations of specific bacteria/plant extracts to limit the presence of AIEC in the ileal mucosa of Crohn's disease patients, presenting a promising approach for disease management.

Digestive health issues, including irregular bowel movements (BM) and gastrointestinal (GI) symptoms, affect millions of people in the United States and are associated with higher risks of various diseases. This randomized, double-blind, placebo-controlled study investigated the potential of Bacillus coagulans Unique IS2 to improve stool characteristics and reduce GI symptoms. Following a 2-week run-in, 144 healthy adults were randomized in a 1:1 ratio to either B. coagulans Unique IS2 (2 billion colony forming units/day) or placebo for 4 weeks. Participants were included if they had an average weekly complete spontaneous bowel movement (SBM) of ≥3.0 and <7.0 during the run-in. The primary outcome was the change in BM frequency after 4 weeks. Secondary outcomes included change in stool consistency (assessed by the Bristol Stool Form Scale), GI symptoms and quality of life, gut microbiota composition, and the proportion of complete SBM to total BM. Safety was assessed by vital signs and reports of adverse events. After 4 weeks of supplementation with Unique IS2, there was a significant increase in BM frequency ( P = 0.037). Stool consistency significantly improved after each week in the Unique IS2 group (all P < 0.05) and was significantly improved compared to a placebo after 4 weeks ( P = 0.018), driven by a significant improvement in the incidence of hard stool ( P = 0.001). There was no effect of Unique IS2 supplementation on GI symptoms and quality of life (Gastrointestinal Quality of Life Index), gut microbiota composition (analysis of stool samples by 16S rRNA), or proportion of complete SBM to total BM. Unique IS2 was safe and well tolerated over the 4 weeks of supplementation. Our results suggest that B. coagulans Unique IS2 is a promising strategy to improve stool characteristics of individuals with hard stools and poor stool quality. Clinicaltrials.gov registration: NCT05123664.

Intrinsic resistant starch type 3 (RS-3) is retrograded starch that is highly resistant to pancreatic digestion (≥80% RS) and will therefore transit to the colon largely intact. Two gut microbes, known as RS degraders, Ruminococcus bromii ATCC27255 and Bifidobacterium adolescentis L2-32, were studied for their ability to degrade intrinsic RS-3 with defined crystal type and chain length (A-type, degree of polymerisation (DP) 16 or DP 21; B-type, DP 32 or DP 76). Remaining glucose, malto-oligosaccharides and non-degraded insoluble RS-3 were quantified over time and remaining RS-3 was visualized by Scanning Electron Microscopy (SEM) over time and compared to degradation of granular maize and potato starch. R. bromii was not limited by any specific physico-chemical starch characteristic and degraded all substrates gradually to primarily maltose and glucose, although these sugars were not further utilised. In contrast, B. adolescentis was unable to degrade B-type intrinsic RS-3 and only slightly fermented A-type intrinsic RS-3 to acetate, whereas granular maize and potato starch were fermented readily to acetate and lactate. The extensive use of SEM in this study revealed the unique morphology of the RS-3 structures and the difference in degradation approach by the two gut microbes. It can be concluded that efficient degradation of intrinsic RS-3 requires microbes with specific enzyme machineries such as those present in R. bromii.

Type-2 diabetes mellitus (T2DM) is associated with a reduction of butyrate-producing gut bacteria. d-allulose and erythritol are low-no-calorie sweeteners (LNCS) used as sugar substitutes to reduce high free sugar intakes associated with non-communicable diseases, including T2DM. This is the first study to investigate the impact of representative and physiologically relevant doses of d-allulose and erythritol on the human gut microbiota of T2DM ( n = 6) and co-living healthy adults ( n = 6). Using the clinically predictive ex vivo SIFR® technology, d-allulose and erythritol were shown to significantly increase butyrate production 24-48h after treatment and significantly increased the abundance of particular microbial families or species in both healthy individuals and those with T2DM compared to the no-substrate control (NSC). d-Allulose significantly increased the abundance of Anaerostipes hadrus and Lachnospiraceae_unclassified_species ( u _ s) at 48h in healthy adults and adults with T2DM compared to the NSC. Erythritol significantly increased the abundance of Eubacteriaceae and Barnesiellaceae families at 48h in healthy adults and adults with T2DM but had no significant effects on microbial species compared to the NSC. d-Allulose resulted in a larger increase in butyrate between 6-24h whereas erythritol resulted in a larger increased butyrate between 24-48h. The findings suggest prebiotic potential of d-allulose and erythritol worth of investigation in human clinical trials, as blending d-allulose and erythritol could be a promising strategy to reduce free sugar intakes and increase butyrate production in both healthy and T2DM individuals, resulting in beneficial effects on glycemic control.

Stress significantly affects gastrointestinal and mental health, and the gut microbiota plays a pivotal role in this process. Enterococcus faecalis strain EC-12 (EC-12) is a lactic acid bacterium that has several health benefits. To investigate the impact of oral supplementation with heat-killed EC-12 on the discomfort caused by stress, a randomised, double-blind, placebo-controlled trial was conducted with students under academic stress taking EC-12 (n= 14) or a placebo (n= 13) daily for one week. Improvement in the students' symptoms was assessed using the visual analogue scale. Faecal microbiota was characterised by next-generation sequencing of 16S rRNA genes, and faecal metabolites and short-chain fatty acids were analysed using a GC-MS metabolomics approach. Significant improvements in abdominal pain and rumbling of the stomach were found in the EC-12 group compared to the placebo group, but no changes were observed in mental symptoms or salivary cortisol levels. The relative abundance of E. faecalis significantly increased in the EC-12 group after the trial; however, the composition and diversity of the gut microbiota did not change significantly. Functional analysis of the gut microbiota suggested that EC-12 intake alters specific metabolic pathways. Although the levels of faecal short-chain fatty acids did not change between the groups before and after the trial, EC-12 intake altered the composition of faecal metabolites, with a significant increase in tryptamine levels. The ratio of students with improved symptoms to those with increased tryptamine levels was calculated based on the number of students with elevated faecal tryptamine levels who showed symptomatic improvements. The ratio of improved rumbling stomach was higher than that of other types of digestive discomfort. These results suggest that oral supplementation with EC-12 has a potentially beneficial effect on stress-induced gastrointestinal discomfort, which may occur through alterations in gut microbiota composition and metabolism. This study was registered at the University Hospital Medical Information Network Center (UMIN) under the UMIN ID: UMIN000048184.

Cow's milk protein allergy (CMPA) in infancy is associated with intestinal microbial dysbiosis, characterised by low Bifidobacteriaceae levels. The present study aimed to investigate the impact of two human milk oligosaccharides (HMO), lactose (L), and their combination on the faecal microbiome and metabolome of infants with CMPA. Stool samples of 12 term infants with probable CMPA (mean age 4.3 months) were analysed using a validated intestinal fermentation assay (SIFR® technology). For each substrate (i.e. HMO (2'-fucosyllactose [2'-FL] and lacto-N-neotetraose [LNnT]), L and HMO + L), taxonomic microbiome characterisation and untargeted metabolite profiling were performed at multiple timepoints. At baseline, the tested faecal microbiota overall displayed low abundances of Bifidobacteriaceae. Fermentation with either HMO or lactose significantly enriched Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium pseudocatenulatum and, for HMO + L, also Bifidobacterium bifidum. The increase in HMO-utilising bifidobacteria was associated with a significant rise in levels of short-chain fatty acids, aromatic lactic acids and N-acetylated amino acids, with additive effects being observed for HMO + L. The above data suggest that the combination of 2'-FL, LNnT and lactose helps to alleviate the previously reported CMPA-associated intestinal bacterial dysbiosis and induces the production of several beneficial metabolites. The clinical significance of these findings for infants with CMPA requires further investigation.