Characterizing the Effects of Calcium and Prebiotic Fiber on Human Gut Microbiota Composition and Function Using a Randomized Crossover Design—A Feasibility Study

Abstract

Consumption of prebiotic inulin has been found to increase calcium absorption, which may protect against gut diseases such as colorectal cancer. This dietary relation may be modulated by compositional changes in the gut microbiota; however, no human study has addressed this hypothesis. We determined the feasibility of a randomized crossover trial to evaluate the effect of three interventions (combined calcium and inulin supplementation, calcium supplementation alone, and inulin supplementation alone) on the intestinal microbiota composition and function. We conducted a 16-week pilot study in 12 healthy adults who consumed the three interventions in a random sequence. Participants provided fecal and blood samples before and after each intervention. Each intervention period lasted four weeks and was flanked by one-week washout periods. 16S ribosomal RNA sequencing and quantification of short chain fatty acids (SCFA) was determined in fecal samples. Systemic lipopolysaccharide binding protein (LBP) was quantified in serum. Of the 12 individuals assigned to an intervention sequence, seven completed the study. Reasons for dropout included time (n = 3), gastrointestinal discomfort (n = 1), and moving (n = 1). Overall, participants reported positive attitudes towards the protocol (n = 9) but were unsatisfied by the practicalities of supplement consumption (44%) and experienced digestive discomfort (56%). We found no appreciable differences in microbial composition, SCFA concentration, nor LBP concentrations when comparing intervention periods. In conclusion, an intervention study using a randomized crossover design with calcium and a prebiotic fiber is feasible. Improvements of our study design include using a lower dose prebiotic fiber supplement and a larger sample size.

Association between gut microbiota and bone metabolism: Insights from bibliometric analysis

“…Prebiotics are non-digestible food components that stimulate the growth of beneficial microorganisms and enhance the activity of the beneficial microbiome ( Sanders et al, 2019 ). Both probiotics and prebiotics have been shown to improve calcium and vitamin D absorption, leading to positive effects on bone formation ( Raveschot et al, 2020 ) ( Yoon and Michels, 2021 ) ( Locantore et al, 2020 ). The first articles reporting the positive effects of probiotics on calcium absorption date back to 2003, and the keyword analysis in our study reveals that fructo-oligosaccharides, a type of prebiotic, first appeared in 2002.…”

Identifying Gut Microbiome Features that Predict Responsiveness Toward a Prebiotic Capable of Increasing Calcium Absorption: A Pilot Study

“…Nonetheless, it is important to compare our findings against other prebiotic fibers. Inulin, a heavily studied prebiotic for bone health was recently evaluated with the gut microbiome in a pilot study of 12 healthy adults [ 23 ]. This study reported increased abundance of Streptococcus and Anaerostipes hadrus in the inulin group compared to calcium supplement only, while Bifidobacteria , Anaerostipes hadrus , and Roseburia intestinalis were more abundant in the inulin group relative to a combined calcium and inulin group.…”

Therapeutic approaches to colorectal cancer via strategies based on modulation of gut microbiota

“…are among the most commonly used probiotics and have favorable effects on various diseases. However, Yoon and Michels (2021) showed in a study that only a specific Bifidobacterium strain improved the effect of cancer treatment. Bifidobacterium breve JCM92 enhanced antitumor immunity by increasing the number of CD8 + T cells and CD8 + effector T cells and increasing the ratios of CD8 + T cells to regulatory T cells and CD8 + effector T cells to regulatory T cells.…”

“…Moreover, it was found that cellulose changed the composition of the gut flora, increased the richness of probiotics, decreased the abundance of inflammatory intestinal bacteria, and inhibited colonic inflammation and tumor formation induced by treatment with azoxymethane/dextran sulfate sodium (Li Q. et al, 2021). Yoon and Michels (2021) found by a feasibility study that combined supplementation with fiber and calcium can prevent CRC via changes in the composition of intestinal microbiota. This is mainly because the consumption of inulin can increase the absorption of calcium.…”