The Combined Effects of Magnesium Oxide and Inulin on Intestinal Microbiota and Cecal Short-Chain Fatty Acids

Abstract

Constipation is a common condition that occurs in many people worldwide. While magnesium oxide (MgO) is often used as the first-line drug for chronic constipation in Japan, dietary fiber intake is also recommended. Dietary fiber is fermented by microbiota to produce short-chain fatty acids (SCFAs). SCFAs are involved in regulating systemic physiological functions and circadian rhythm. We examined the effect of combining MgO and the water-soluble dietary fiber, inulin, on cecal SCFA concentration and microbiota in mice. We also examined the MgO administration timing effect on cecal SCFAs. The cecal SCFA concentrations were measured by gas chromatography, and the microbiota was determined using next-generation sequencing. Inulin intake decreased cecal pH and increased cecal SCFA concentrations while combining MgO increased the cecal pH lowered by inulin and decreased the cecal SCFA concentrations elevated by inulin. When inulin and MgO were combined, significant changes in the microbiota composition were observed compared with inulin alone. The MgO effect on the cecal acetic acid concentration was less when administered at ZT12 than at ZT0. In conclusion, this study suggests that MgO affects cecal SCFA and microbiota during inulin feeding, and the effect on acetic acid concentration is time-dependent.

Nutritional Support: The Use of Antioxidants in Inflammatory Bowel Disease

“…Del Chierico et al showed that magnesium can alleviate colitis in mice by increasing short-chain fatty acids (SCFA) and reducing the number of bacteria involved in inflammation [123]. Omori et al in a study in mice showed that MgO along with inulin administration increased intestinal pH but also decreased levels of SCFA and lactic acid [124]. Intestinal bacteria such as Lactobacillus spp.…”

The Effects of the Mediterranean Diet on Health and Gut Microbiota

“…Magnesium: There is some evidence that magnesium orotate may modulate the microbiome-gut-brain axis and that this, combined with probiotic supplementation, may improve some aspects of gastrointestinal and psychiatric disorders that are associated with dysbiosis [84]. In a rodent-based study, it was shown that the addition of magnesium oxide to an inulin-based diet resulted in significant changes to gut microbiota composition and caecal SCFAs [85]. In a further rodent-based study, it was shown that magnesium deficiency within the diet altered gut microbiota and was associated with altered anxiety-like behaviour [86].…”

Effect of magnesium oxide with probiotics on bowel movements in elderly orthopedic patients with chronic constipation: a retrospective chart review

“…Unlike stimulant laxatives, MgO was thought not to lose its efficacy with continuous use, but in some cases, long-term administration of MgO has worsened defecation [6]. Recent animal experiments have shown that dietary fiber is fermented by intestinal bacteria to produce short-chain fatty acids (SCFAs), which improve the intestinal environment and chronic constipation, but this constipation-improving effect disappeared when MgO was used [7]. The mechanism by which MgO eliminates this constipation-improving effect is an increase in intestinal pH together with a concomitant change in the composition of the intestinal microbiota and a 5 decrease in the production of SCFAs [7].…”

“…Recent animal experiments have shown that dietary fiber is fermented by intestinal bacteria to produce short-chain fatty acids (SCFAs), which improve the intestinal environment and chronic constipation, but this constipation-improving effect disappeared when MgO was used [7]. The mechanism by which MgO eliminates this constipation-improving effect is an increase in intestinal pH together with a concomitant change in the composition of the intestinal microbiota and a 5 decrease in the production of SCFAs [7]. On the other hand, the guidelines for chronic constipation place probiotics at a recommendation level of 2 and a level of evidence of B [5].…”