Cindy Duysburgh

Objective: To define the potential functional roles of a herbal preparation of myrrh, chamomile extract, and coffee charcoal in patients suffering from diarrhea dominant irritable bowel syndrome (IBS-D). Methods: The study utilized the Mucosal Simulator of the Human Intestinal Microbial Environment (M-SHIME ^® ) with proximal (PC) and distal colon (DC) compartments and fecal samples from four IBS-D donors. Eight-day (d) repeated dosing with the herbal product (6 tablets/day) was initiated compared to a negative control. Changes in microbial metabolism and community composition were assessed, and colonic ferments were evaluated for their effects on intestinal barrier permeability and cytokine production in a Caco-2/THP-1 co-culture model. Results: Product treatment significantly increased gas pressure versus negative control, indicating microbial fermentative activity. Product supplementation significantly increased proximal acetate (d3, d5), propionate (d3), and butyrate (d5, d8) levels (p < 0.05 for all), while no significant changes were observed distally. Ammonium levels were significantly elevated following product supplementation in PC (d3, d5, d8; p < 0.05) and DC (d8; p < 0.01), though remained within physiological range. Repeated dosing enriched members of Bifidobacteriaceae , Bacteroidota, Lachnospiraceae , and Butyricicoccus versus negative control. Treated colonic ferments had a protective effect on intestinal membrane integrity (DC; p < 0.001) and positive immunomodulatory effects (increased IL-10, PC and DC [both p < 0.0001], and IL-6, PC [p < 0.001] and DC [p < 0.01]) in Caco-2/THP-1 co-cultures. Conclusions: Treatment with a herbal preparation of myrrh, chamomile extract, and coffee charcoal showed a potential beneficial effect on the microbiota of patients with IBS-D in vitro , suggesting further exploration of its efficacy in IBS-D and other chronic gastrointestinal disorders.

Objective: This study assessed the ability of capsule formulations to improve the oral delivery and retain activity of an acid-sensitive enzyme during gastrointestinal transit. Methods: The dissolution characteristics of five capsule formulations—single DRcaps^® [DR], single Vcaps^® Plus [VCP], and three DUOCAP^® capsule-in-capsule combinations, DRcaps^® inside DRcaps^® (DR-in-DR), DRcaps^® inside Vcaps^® Plus (DR-in-VCP), and Vcaps^® Plus inside DRcaps^® (VCP-in-DR)—were evaluated in an in vitro simulation of a healthy human upper gastrointestinal tract under fasting and fed conditions using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME)^® platform. Capsules contained caffeine as a marker of capsule dissolution, and pancreatin as an active ingredient for which activity was determined by the conversion of tributyrin. Readouts included visual capsule scoring, the analysis of caffeine release, and the quantification of tributyrin-to-butyrate conversion at the end of each gastrointestinal tract segment. Results: The single VCP capsules had a high level of caffeine release at the end of the stomach incubation with low butyrate recovery (16–21%), suggesting the rapid release and gastric degradation of the unprotected enzyme. The single DR, DR-in-VCP, and VCP-in-DR formulations showed caffeine release at the end of the duodenum and/or jejunum and had high butyrate recovery, ranging from 53% to 87%. The DR-in-DR formulation had the most delayed release, with incomplete caffeine release and low-to-moderate butyrate recovery (10–36%). Conclusions: Fast capsule dissolution led to the reduced enzymatic activity of the active ingredient, while delayed dissolution resulted in inadequate time for the enzymatic conversion of tributyrin to butyrate. These results highlight that capsule selection should align with the intended use and targeted nutrient delivery, with DUOCAP^® formulations being best suited for small intestinal (VCP-in-DR and DR-in-VCP) and colonic (DR-in-DR) delivery.

In dogs, gut microbiome dysbiosis is associated with several health conditions, including gastrointestinal disease. Probiotic supplementation can support a balanced gut microbiome. This study assessed the impact of a probiotic containing a mixture of Lacticaseibacillus casei, Limosilactobacillus fermentum, Levilactobacillus brevis, and Enterococcus faecium on the gut microbiota of six dogs using short-term colonic simulations. Two groups were included, i.e., blank versus supplementation with the test product, and incubated for 48 h. Probiotic-supplemented reactors had significantly greater fermentative activity compared with the blank, as shown by lower pH levels and higher gas pressure after 6 h, 24 h, and 48 h of incubation (p < 0.05 for all). Saccharolytic fermentation also increased, with a significantly higher level of acetate at 24 h and propionate at 6 h, 24 h, and 48 h with the test product versus blank (p < 0.05 for all). There was no significant effect of the test product on alpha-diversity, but beta-diversity analysis revealed a clear separation in the microbial community composition between the test product and blank. Eight bacterial taxa were enriched with test product supplementation, including the probiotic test strains as well as Megamonas and Bacteroides species. This study, using in vitro short-term colon simulations with six canine donors, provides insights into the probiotic characteristics of the test product.

Background/Objectives: The probiotic Lacticaseibacillus paracasei DG (LpDG) has shown promising results for various gastrointestinal diseases. This study evaluated the survival, metabolic activity, and impact on colonic microbiota of LpDG in an in vitro gastrointestinal tract simulation. Methods: Encapsulated LpDG was tested under simulated fed, fasted, and shortened fasted conditions compared with a blank control in a modified Simulator of the Human Intestinal Microbial Ecosystem (SHIME^®) reactor. Capsule integrity, and cell culturability and viability were assessed at the end of each digestion phase. Metabolic activity (pH, total gas production, and concentrations of short-chain fatty acids, lactate, and ammonium) was assessed after a 24 h colonic incubation with a faecal inoculum. The impact of LpDG on the colonic microbial community was analysed by quantitative polymerase chain reaction and shallow shotgun sequencing. Results: The capsule was completely degraded at the end of the jejunum under all conditions. A low pH had a minimal impact on LpDG culturability and viability. Compared with blank control, LpDG remained metabolically active in the microbial community following a 24 h colonic incubation (LpDG [0–24 h] vs. blank control [0–24 h]: ΔpH, decreased [0.29–0.38 vs. 0.12–0.34]; Δlactic acid, decreased [1.52–1.69 mM vs. 0.13–0.21 mM]; and Δbutyrate, increased [7.49–10.52 mM vs. 5.19–7.76 mM]). Under fed conditions, treatment with LpDG compared with blank control significantly decreased levels of Escherichia coli and Blautia wexlerae and increased Clostridiaceae, Eubacteriaceae, and Lachnospiraceae. Conclusions: LpDG remains viable and metabolically active in the gastrointestinal tract, positively affecting intestinal microbiota and metabolite production.

Fucoidans have demonstrated a wide range of bioactivities including immune modulation and benefits in gut health. To gain a deeper understanding on the effects of fucoidan from Undaria pinnatifida (UPF) on the colonic microbiome, the short-term Simulator of the Human Intestinal Microbial Ecosystem^®, a validated in vitro gut model, was applied. Following a three-week intervention period on adult faecal samples from three healthy donors, microbial community activity of the colonic microbiota was assessed by quantifying short-chain fatty acids while composition was analysed utilising 16S-targeted Illumina sequencing. Metagenomic data were used to describe changes in community structure. To assess the secretion of cytokines, co-culture experiments using Caco-2 and THP1-Blue™ cells were performed. UPF supplementation over a three-week period had a profound butyrogenic effect while also enriching colonic microbial diversity, consistently stimulating saccharolytic genera, and reducing genera linked with potentially negative health effects in both regions of the colon. Mild immune modulatory effects of UPF were also observed. Colonic fermentation of UPF showed anti-inflammatory properties by inducing the secretion of the anti-inflammatory cytokines IL-6 and IL-10 in two out of three donors in the proximal and distal colon. In conclusion, UPF supplementation may provide significant gut health benefits.

This study evaluated the impact of a proprietary blend of fruit and vegetable fibers rich in naturally occurring bound polyphenols (commercially marketed as NatureKnit^TM), compared to purified fibers (inulin and psyllium), on the human gut microbiome using the validated M-SHIME^® gastrointestinal model. A short-term single-stage colonic M-SHIME^® experiment (with fecal inoculum from three healthy human donors) was used to evaluate the test products compared to a negative control. Samples were assessed for pH, gas pressure, short-chain fatty acid (SCFA) production, lactate, and ammonium from 0 h to 48 h. Microbial community composition was assessed at 0 h (negative control only), 24 h, and 48 h (lumen) or 48 h (mucosal). All test products were fermented well in the colon as demonstrated by decreases in pH and increases in gas pressure over time; these changes occurred faster with the purified fibers, whereas NatureKnit™ demonstrated slow, steady changes, potentially indicating a gentler fermentation process. SCFA production significantly increased over the course of the 48 h experiment with all test products versus negative control. SCFA production was significantly greater with NatureKnit™ versus the purified fibers. Shifts in the microbial community composition were observed with all test products versus negative control. At the conclusion of the 48 h experiment, the absolute bacterial abundance and the richness of observed bacterial taxa in the lumen compartment was significantly greater with NatureKnit™ compared with inulin, psyllium, and negative control. Overall, NatureKnit™ demonstrated greater or similar prebiotic effects on study measures compared with established prebiotic fibers.

Bread can vary in textural and nutritional attributes based on differences in the bread making process (e.g., flour type, fermentation agent, fermentation time). Four bread recipes (BRs) made with sourdough preferments (BR1, white flour; BR2, whole grain flour) or regular yeast breads (BR3, white flour; BR4, whole grain flour) were evaluated for texture, digestibility, and their effect on the metabolic activity and composition of the gut microbiota using texture profile analysis (TPA) coupled with in vitro upper gastrointestinal (GIT) digestion and colonic fermentation (Colon-on-a-plate™ model), using fecal samples from eight healthy human donors. TPA revealed significantly higher values for hardness, fracturability, gumminess, and chewiness, and significantly lower values for springiness, cohesiveness, and resilience with whole grain versus white breads (all p < 0.001); values for springiness, cohesiveness, and resilience were significantly higher for sourdough versus yeast bread (p < 0.001). Nutrient composition and bioaccessibility were generally comparable between sourdough and yeast bread with similar flours. Following simulation of upper GIT digestion, all BRs demonstrated good digestibility of minerals, carbohydrates, and proteins. Colonic fermentation revealed changes in gut microbiota composition, significant increases in short-chain fatty acids, and a significant decrease in branched short-chain fatty acids with all BRs versus a blank. Overall, new insights into wheat bread digestibility and colonic fermentation were provided, which are important aspects to fully characterize bread nutritional profile and potential.

Many health-promoting effects have been attributed to the intake of probiotic cells. However, it is important that probiotic cells arrive at the site of their activity in a viable state in order to exert their beneficial effects. Careful selection of the appropriate probiotic formulation is therefore required as mainly the type of probiotic species/strain and the administration strategy may affect survival of the probiotic cells during the upper gastrointestinal (GIT) passage. Therefore, the current study implemented Simulator of the Human Microbial Ecosystem (SHIME^®) technology to investigate the efficacy of different commercially available probiotic formulations on the survival and culturability of probiotic bacteria during upper GIT passage. Moreover, Colon-on-a-Plate (CoaP™) technology was applied to assess the effect of the surviving probiotic bacteria on the gut microbial community (activity and composition) of three human donors. Significantly greater survival and culturability rates were reported for the delayed-release capsule formulation (>50%) as compared to the powder, liquid, and standard capsule formulations (p < 0.05), indicating that the delayed-release capsule was most efficacious in delivering live bacteria cells. Indeed, administration of the delayed-release capsule probiotic digest resulted in enhanced production of SCFAs and shifted gut microbial community composition towards beneficial bacterial species. These results thus indicate that careful selection of the appropriate probiotic formulation and administration strategy is crucial to deliver probiotic cells in a viable state at the site of their activity (distal ileum and colon).

Nutritional interventions to reduce gastrointestinal (GI) permeability are of significant interest to physically active adults and those experiencing chronic health conditions. This in vitro study was designed to assess the impact of AG1, a novel synbiotic, on GI permeability following an inflammatory challenge. Interventions [AG1 (vitamins/minerals, pre-/probiotics, and phytonutrients) and control (control medium)] were fed separately into a human GI tract model (stomach, small intestine, and colon). In the colonic phase, the GI contents were combined with fecal inocula from three healthy human donors. GI permeability was evaluated with transepithelial electrical resistance (TEER) in a Caco-2 (apical)/THP1-Blue™ (basolateral) co-culture model. The apical side received sodium butyrate (positive control) or Caco-2 complete medium (negative control) during baseline testing. In the 24 h experiment, the apical side received colonic simulation isolates from the GI model, and the basolateral side was treated with Caco-2 complete medium, then 6 h treatment with lipopolysaccharide. TEER was assessed at 0 h and 24 h, and inflammatory markers were measured at 30 h in triplicate. Paired samples t-tests were used to evaluate endpoint mean difference (MD) for AG1 vs. control. TEER was higher for AG1 (mean ± SD: 99.89 ± 1.32%) vs. control (mean ± SD: 92.87 ± 1.22%) following activated THP1-induced damage [MD: 7.0% (p < 0.05)]. AG1 maintained TEER similar to the level of the negative control [−0.1% (p = 0.02)]. No differences in inflammatory markers were observed. These in vitro data suggest that acute supplementation with AG1 might stimulate protective effects on GI permeability. These changes may be driven by SCFA production due to the pre-/probiotic properties of AG1, but more research is needed.

Arabic gum, a high molecular weight heteropolysaccharide, is a promising prebiotic candidate as its fermentation occurs more distally in the colon, which is the region where most chronic colonic diseases originate. Baobab fiber could be complementary due to its relatively simple structure, facilitating breakdown in the proximal colon. Therefore, the current study aimed to gain insight into how the human gut microbiota was affected in response to long-term baobab fiber and Arabic gum supplementation when tested individually or as a combination of both, allowing the identification of potential complementary and/or synergetic effects. The validated Simulator of the Human Intestinal Microbial Ecosystem (SHIME^®), an in vitro gut model simulating the entire human gastrointestinal tract, was used. The microbial metabolic activity was examined, and quantitative 16S-targeted Illumina sequencing was used to monitor the gut microbial composition. Moreover, the effect on the gut microbial metabolome was quantitatively analyzed. Repeated administration of baobab fiber, Arabic gum, and their combination had a significant effect on the metabolic activity, diversity index, and community composition of the microbiome present in the simulated proximal and distal colon with specific impacts on Bifidobacteriaceae and Faecalibacterium prausnitzii. Despite the lower dosage strategy (2.5 g/day), co-supplementation of both compounds resulted in some specific synergistic prebiotic effects, including a biological activity throughout the entire colon, SCFA synthesis including a synergy on propionate, specifically increasing abundance of Akkermansiaceae and Christensenellaceae in the distal colon region, and enhancing levels of spermidine and other metabolites of interest (such as serotonin and ProBetaine).