In vitro Selection of Probiotics for Microbiota Modulation in Normal-Weight and Severely Obese Individuals: Focus on Gas Production and Interaction With Intestinal Epithelial Cells

Abstract

The intestinal microbiota plays important roles in the maintenance of health. Strategies aiming at its modulation, such as probiotics, have received a deal of attention. Several strains have been studied in different in vitro models; however, the correlation of results obtained with the in vivo data has been limited. This questions the usefulness of such in vitro selection models, traditionally relying on over-simplified tests, not considering the influence of the accompanying microbiota or focusing on microbiota composition without considering functional traits. Here we assess the potential of six Bifidobacterium, Lactobacillus and Lacticaseibacillus strains in an in vitro model to determine their impact on the microbiota not just in terms of composition but also of functionality. Moreover, we compared the responses obtained in two different population groups: normal-weight and severely obese subjects. Fecal cultures were conducted to evaluate the impact of the strains on specific intestinal microbial groups, on the production of short-chain fatty acids, and on two functional responses: the production of gas and the interaction with human intestinal epithelial cells. The response to the different probiotics differed between both human groups. The addition of the probiotic strains did not induce major changes on the microbiota composition, with significant increases detected almost exclusively for the species added. Higher levels of gas production were observed in cultures from normal-weight subjects than in the obese population, with some strains being able to significantly reduce gas production in the latter group. Moreover, in obese subjects all the Bifidobacterium strains tested and Lacticaseibacillus rhamnosus GG were able to modify the response of the intestinal cells, restoring values similar to those obtained with the microbiotas of normal-weight subjects. Our results underline the need for the screening and selection of probiotics in a target-population specific manner by using appropriate in vitro models before enrolling in clinical intervention trials.

Influence of 2′-Fucosyllactose on the Microbiota Composition and Metabolic Activity of Fecal Cultures from Breastfed and Formula-Fed Infants at Two Months of Age

“…This age was decided based on a minimum time of exposure of babies to the different feeding types as to promote early differences on microbiota profile and whenever enough amount of feces from babies can be guaranteed to carry out experiments. The ANKOM RF system for in vitro batch fermentations used in the present study has been previously employed to assess the efficacy of probiotics and prebiotics to modulate microbiota of extreme obese and normal weight adults [ 22 , 31 ]. The BMIF basal medium was previously optimized to allow a balanced short-term growth of intestinal microorganisms from infant feces [ 20 ].…”

In Vitro Probiotic Modulation of the Intestinal Microbiota and 2′Fucosyllactose Consumption in Fecal Cultures from Infants at Two Months of Age

“…Among these combinations, those corresponding exclusively to cultures with 2 FL have been published elsewhere [7] and are used in the present work for comparison with the cultures supplemented with probiotics. Briefly, the pre-reduced medium was inoculated with the corresponding fecal homogenates (1%, v/v), distributed into bottles of the ANKOM RF system (Ankom Technology, Macedon, NY, USA), and stabilized in anaerobiosis [23]. Then, 2 FL preparations were added to the corresponding bottles at a final concentration of 0.2% (w/v), and bacterial suspensions, prepared in the day of the assay, were added at the final levels of 2.4 × 10 7 cfu/mL for L. helveticus and 3 × 10 6 for B. longum subsp.…”

“…The pH of fecal cultures (time 0 and after 24 h of incubation) and the cumulative gas produced during the different fermentation conditions using the ANKOM RF system were determined as described previously [7,23].…”

Altered gut microbial functional pathways in people with Irritable Bowel Syndrome enable precision health insights

“…Probiotics observed to produce GABA are also supplemented [132][133][134]. Excessive sulfide and methane gas, as indicated by "Not Optimal" SulfideProductionPathways and MethanogenesisPathways scores, are addressed through the restriction of sulfur containing substrates known to increase the microbial production of sulfide gas; the restriction of substrates like carnitine, choline, and fructooligosaccharides known to contribute to the production of microbial methane gas; as well as the introduction of polyphenols, prebiotics, and probiotics shown to reduce both the abundance and activity of gas producing microbes [135][136][137][138][139][140][141][142][143][144][145]. The impact these and other personalized interventions have on gastrointestinal function and mental health are currently being investigated (ClinicalTrials.gov ID's NCT06190184; NCT05465629.…”