Total Transit Time and Probiotic Persistence in Healthy Adults: A Pilot Study.

Background/Aims: Motility, stool characteristics, and microbiota composition are expected to modulate probiotics' passage through the gut but their effects on persistence after intake cessation remain uncharacterized. This pilot, open-label study aims at characterizing probiotic fecal detection parameters (onset, persistence, and duration) and their relationship with whole gut transit time (WGTT). Correlations with fecal microbiota composition are also explored. Methods: Thirty healthy adults (30.4 ± 13.3 years) received a probiotic (30 × 109 CFU/capsule/day, 2 weeks; containing Lactobacillus helveticus R0052, Lacticaseibacillus paracasei HA-108, Bifidobacterium breve HA-129, Bifidobacterium longum R0175, and Streptococcus thermophilus HA-110). Probiotic intake was flanked by 4-week washout periods, with 18 stool collections throughout the study. WGTT was measured using 80% recovery of radio-opaque markers. Results: Tested strains were detected in feces ~1-2 days after first intake and persistence after intake cessation was not significantly different for R0052, HA-108, and HA-129 (~3-6 days). We identified 3 WGTT subgroups within this population (named Fast, Intermediate, and Slow), which could be classified by machine learning with high accuracy based on differentially abundant taxa. On average, R0175 persisted significantly longer in the intermediate WGTT subgroup (~8.5 days), which was mainly due to 6 of the 13 Intermediate participants for whom R0175 persisted ≥ 15 days. Machine learning classified these 13 participants according to their WGTT cluster (≥ 15 days or < 5 days) with high accuracy, highlighting differentially abundant taxa potentially associated with R0175 persistence. Conclusion: These results support the notion that host-specific parameters such as WGTT and microbiota composition should be considered when designing studies involving probiotics, especially for the optimization of washout duration in crossover studies but also for the definition of enrollment criteria or supplementation regimen in specific populations.

Recommending ultra-processed oral nutrition supplements for unintentional weight loss: Are there risks?

Oral nutrition supplements (ONS) are widely recommended for the management of unintentional weight loss in patient populations, long-term care residents, and community-dwelling older adults. Most marketed ONS are ultra-processed, with precision nutrition and aseptic composition, as well as convenience and availability, driving their selection. However, therapeutic effectiveness is mixed and the potential health risks of consuming ultra-processed ONS long-term in lieu of less-processed foods have received little attention. A diverse and balanced microbiota supporting immunity and wellness is maintained by a diet rich in plant-sourced foods. The implications of ultra-processed ONS displacing plant-sourced foods, and specifically the potential for undesirable impacts on the gut microbiota, require consideration. Most ONS are either devoid of fiber or are supplemented with isolated or purified fibers that may contribute to adverse gastrointestinal symptoms and appetite suppression. In contrast, the diversity of microbial-available, nondigestible carbohydrates, together with the array of phytochemicals found in plant-sourced foods, support microbial diversity and its resiliency. This review outlines the clinical dilemma of recommending commercial ultra-processed ONS vs nutritionally adequate (eg, high-energy/high-protein) foods and beverages that contribute to diet quality, maintenance of a diverse and stable gut microbiota composition, and support nutrition status and health. Ultra-processed ONS may fall short of expected health benefits, and overreliance may potentially contribute to the risk for patient and older adult populations because of the displacement of a variety of healthful foods.

Fermented soy supplementation improves indicators of quality of life: a randomized, placebo-controlled, double-blind trial in adults experiencing heartburn.

OBJECTIVE: To determine if fermented soy supplementation relieves heartburn and improves gastrointestinal symptoms and quality of life, a randomized, double-blind parallel study was conducted with adults experiencing mild or moderate heartburn. Participants consumed up to 3, 1 g sachets of flavored, Lactobacillus delbrueckii fermented with soy flour (n = 23) or placebo (maltodextrin) (n = 27) sachets per heartburn incident as needed for 3 weeks. Symptom intensity at 5, 15, and 30 min post-administration was assessed using a Likert-like scale. The Gastrointestinal Symptoms Rating Scale (GSRS) and Gastro-esophageal Reflux Disease Quality of Life Questionnaire (GERD-QOL) were administered at baseline, post-intervention and following a 1-week washout. RESULTS: No significant differences between groups were seen for heartburn severity or frequency, GSRS syndromes, or GERD-QOL domains. However, individual QOL items related to inconvenience of taking medications, fear of eating, inability to concentrate at work, and disturbance of after-meal activities and rest improved with fermented soy compared to placebo. Frequency of heartburn, diarrhea, and bloating improved during washout vs. baseline for the fermented soy group compared to placebo. Lactobacillus delbrueckii fermented soy supplementation improved QOL indicators and may decrease heartburn occurrence over time vs. an acute effect; efficacy of daily intake and longer duration requires investigation.

Diet, nutrients and the microbiome.

Although there is associative evidence linking fecal microbiome profile to health and disease, many studies have not considered the confounding effects of dietary intake. Consuming food provides fermentable substrate which sustains the microbial ecosystem that resides with most abundance in the colon. Western, Mediterranean and vegetarian dietary patterns have a role in modulating the gut microbiota, as do trending restrictive diets such the paleolithic and ketogenic. Altering the amount or ratio of carbohydrate, protein and fat, particularly at the extremes of intake, impacts the microbiome. Diets high in fermentable carbohydrates support the relative abundance of Bifidobacterium, Prevotella, Ruminococcus, Dorea and Roseburia, among others, capable of degrading polysaccharides, oligosaccharides and sugars. Conversely, very high fat diets increase bile-resistant organisms such as Bilophila and Bacteroides. Food form, whole foods vs. ultra-processed, alters the provision of macronutrient substrate to the colon due to differing digestibility, and thereby may impact the microbiota and its metabolic activity. In addition, phytochemicals in plant-based foods have specific and possibly prebiotic effects on the microbiome. Further, food ingredients such as certain low-calorie sweeteners enhance Bifidobacterium spp. The weight of evidence to date suggests a high level of interindividual variability in the human microbiome vs. clearly defined, dietary-induced profiles. Healthful dietary patterns, emphasizing plant foods high in microbial-available carbohydrate, support favorable microbiome profiles active in saccharolytic fermentation. Future research into diet and microbiome should consider the balance of gut microbial-generated metabolites, an important link between microbiome profile and human health.