Administration of Inulin-Supplemented Gluten-Free Diet Modified Calcium Absorption and Caecal Microbiota in Rats in a Calcium-Dependent Manner

Abstract

In coeliac disease (CD), the risk of adverse calcium balance and reduced bone density is induced mainly by the disease, but also by a gluten-free diet (GFD), the only accepted CD therapy. Prebiotics through the beneficial impact on intestinal microbiota may stimulate calcium (Ca) absorption. In the present study, we hypothesised that the dietary inulin in GFD would influence positively the intestinal microbiota, and by that will stimulate the absorption of calcium (Ca), especially in the conditions of Ca malnutrition. In a six-weeks nutritional experiment on growing a significant (p < 0.05) luminal acidification, decrease in ammonia concentration and stimulation of short chain fatty acids formation indicated inulin-mediated beneficial effects on the caecal microbiota. However, the effect of inulin on characteristics of intestinal microbiota and mineral utilization depended on the dietary Ca intake from GFDs. Inulin stimulated bifidobacteria, in particular B. animalis species, only if a recommended amount of Ca was provided. Most benefits to mineral utilization from inulin consumption were seen in rats fed Ca-restricted GFD where it increased the relative Ca absorption. Administration of inulin to a GFDs could be a promising dietary strategy for beneficial modulation of intestinal ecosystem and by that for the improvement the Ca absorption.

Calcium Oxalate Nephrolithiasis and Gut Microbiota: Not just a Gut-Kidney Axis. A Nutritional Perspective

“…Reduced or excessive calcium intake could also influence the development of obesity through modulation of microbiota in weaning mouse pups [126]. Moreover, modulation of microbiota through prebiotic supplements can positively modulate dietary calcium absorption in mice, which represents a promising strategy for reducing the burden of hypercalciuria in kidney stone formers [127].…”

Characterization, health benefits and applications of fruits and vegetable probiotics

“…Moreover, prebiotics may provide direct benefits to human health through cholesterol removal, lowering blood sugar, prevention of obesity, relieving constipation and inhibition of pathogens and carcinogens (Mohanty et al, 2018;Zhang et al, 2015). At the same time, they support intestinal and immune system functioning and improves calcium and magnesium absorption (Krupa-Kozak et al, 2017;Mohanty et al, 2018). Generally, fermented FV as prebiotics require few ingredients and minimal processing steps even though some contains only few dominant microbial taxa with remarkably complex population dynamics (Marco et al, 2017).…”

Prebiotics, Bone and Mineral Metabolism

“…The majority of literature to support the effects of prebiotics on bone comes from animal research with a small portion from in vitro cell studies. Together, this literature provides the strongest support for mechanisms of action while also characterizing interactions between prebiotic type and calcium dose when evaluating bone outcomes [ 91 , 92 ]. Preclinical studies also provide ample evidence for prebiotic effects on bone throughout the life course as evidence is available from young, adult, and elderly animal models.…”

“… 114 ) Inulin 7% inulin solution (v/w) Parallel design; 4 diets: gluten-free diets with either the appropriate Ca content or reduced Ca content, or gluten-free diets with adequate or reduced Ca plus inulin Male Wistar rats ( n = 32), age 4 weeks Ca, Mg, and P balance; fecal SCFA concentration; microbial community analysis by PCR-DGGE and quantitative rt-qPCR of 16S rRNA gene Diets with inulin resulted in increased mineral absorption; Ca content of the diet influenced Ca, P, and Mg absorption; inulin stimulated fecal bifidobacteria content when dietary Ca was adequate; SCFA content in cecum was influenced by interaction between dietary Ca and inulin Krupa-Kozak U, et al 2017 (Ref. 92 ) inulin 0, 5, 10 and 20% inulin, for 21 days Parallel design Male Wistar rats ( n = 24), age 6 week Apparent Ca absorption, cecal pools of Ca, P and Mg; cecal wall and content weights, pH and SCFA content Inulin increased the cecal pool of Ca and P and to a lesser degree Mg; absorption of Ca was improved in a dose-dependent manner; total SCFA increased with inulin treatment; propionate content was increased with 10% inulin treatment relative to control Levrat M, et al 1991 (Ref. 99 ) Inulin 10% inulin, for 15 days Parallel design; rats were stratified based on body weight; run-in diet for 7 days prior to treatments which were modified from AIN-93G diet; 4 diets: 15% soy bean oil (SO), 15% Soy bean oil + EPA + DHA (FSO), 15% SO + 10% Synergy1 ® or 15% FSO + 10% Synergy1 ® Male Wistar rats ( n = 24), age 6 week Apparent mineral absorption and balance for Ca, Mg, Cu, Fe and Zn; bone mineral and biomechanical assessments (bone breaking); tibia and femur Ca and Zn content; tibia strength measures; cecal morphology and pH Inulin improved apparent mineral absorption of Ca, Mg, Cu, Fe and Zn but FO and SO appeared to differentially influence absorption; FO negatively affected Mg absorption, while FSO potentiated the effects of inulin for Ca absorption and balance, and Cu, Fe and Zn absorption; bone Ca and Zn content were enhanced most by FSO + inulin; compared with controls, inulin increased cecal weight, number of crypts and cell density, and decreased cecal content pH Lobo A, et al 2009 (Ref.…”