Association Between Gut Microbiota and Insulin Therapy in Women With Gestational Diabetes Mellitus

OBJECTIVES

At the time of diagnosis, the blood glucose of women with gestational diabetes mellitus (GDM) who require subsequent insulin treatment does not differ from that of women with adequate diet control. Hence, in this study, we aimed to determine the role of maternal gut microbiota as a marker of insulin necessity in GDM and to identify the effect of insulin therapy on gut microbiota composition in mothers with GDM and their newborns.

METHODS

Seventy-one pregnant women were enrolled into the study, including 38 GDM and 33 non-GDM participants. During the follow-up period, 8 of the 38 GDM subjects required insulin therapy (GDM-I group), whereas 30 of the 38 GDM cases with sufficient glycemic control by diet alone (GDM-D group). Maternal blood and feces were obtained at the time of GDM diagnosis (pretreatment; 24 to 28 weeks of gestation) and before delivery (posttreatment; ≥37 weeks of gestation). Meconium and first feces of the newborns were also collected.

RESULTS

Pretreatment, the glycemic profile did not differ between the GDM-D and GDM-I groups. However, the proportions of Clostridiales, Lactobacillus and Bacteroidetes were higher in the GDM-I group than in the non-GDM and GDM-D groups. After treatment, gut microbiota composition showed no difference between non-GDM and GDM-I groups. Interestingly, a higher Firmicutes/Bacteroidetes (F/B) ratio was displayed in GDM-D mothers at posttreatment, and this was also observed in both meconium and first feces of GDM-D newborns.

CONCLUSION

Insulin therapy changed maternal gut microbiota composition, which could be transferable to the mothers' newborns.

The effect of Escherichia coli ŽP strain with a conjugation-based colicin E7 delivery on growth performance, hematological, biochemical, and histological parameters, gut microbiota, and nonspecific immunity of broilers

The Escherichia coli ŽP strain (ŽP) was constructed based on the known probiotic E. coli strain Nissle 1917. It was genetically modified to carry the colicin E7 synthesis gene encoding DNase on a conjugative plasmid and the colicin E7 immunity gene in the chromosome. The aim of this study was to evaluate the effects of the daily ŽP per oral administration (5 × 10⁸ or 5 × 10¹⁰ CFU per bird) on the growth performance, hematological, biochemical, histological parameters, gut microbiota, and nonspecific immunity of the 4-24 days old broilers. The ŽP administration increased the abundance of genera Bacillus, Butyrivibrio, and Clostridium and did not influence the weight gain of 4-16 days old broilers. The biochemical parameters were within normal ranges for poultry in experimental and control groups. The ŽP administration had no effect on the erythrocyte numbers, hemoglobin and immunoglobulin Y concentrations, but significantly increased the serum lysozyme concentration, leukocyte numbers, and reactive oxygen species production by phagocytes compared with the control group. It did not cause inflammatory changes in intestinal mucosa, Peyer's patches, and spleen. Thus, the ŽP had no detrimental effects on broiler health and could be an efficient probiotic for the broiler colibacillosis prophylaxis.

Trimethylamine N-oxide promotes hyperlipidemia acute pancreatitis via inflammatory response

Trimethylamine N-oxide (TMAO), a metabolite of gut microbiota, is involved in the regulation of lipid metabolism and inflammatory response; however, the role of TMAO in hyperlipidemia acute pancreatitis (HAP) is not clear. In this study, HAP mice were used as an animal model to explore the effects and possible mechanism of TMAO on HAP, which may provide new ideas for the treatment of HAP. Results found that the levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, nonestesterified fatty acid, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, α-amylase, TMAO, and flavin-containing monooxygenase 3 were significantly increased, the levels of high-density lipoprotein cholesterol and insulin were significantly decreased, and there was an obvious pancreatic injury and inflammatory response in the model group. The choline analogue 3,3-dimethyl-1-butanol (DMB) treatment reversed the changes of serum biochemical parameters, alleviated the pancreatic tissue injury, and reduced the levels of inflammatory cytokines. Further studies of toll-like receptor (TLR)/p-glycoprotein 65 (p65) pathway found that the expressions of TLR2, TLR4, and p-p65/p65 in the model group were significantly increased, which was more obvious after Escherichia coli (Migula) Castellani & Chalmers treatment, while activation of the TLR/p65 pathway was inhibited by DMB. The results indicated that TMAO promotes HAP by promoting inflammatory response through TLR/p65 signaling pathway, suggesting that TMAO may be a potential target of HAP.

Green banana flour supplementation improves obesity-associated systemic inflammation and regulates gut microbiota profile in mice fed high-fat diets

This study evaluated the effect of green banana flour (GBF) consumption on obesity-related conditions in mice fed high-fat diets. GBF was prepared using stage 1 green banana pulp, which was dehydrated and milled. Mice were fed a control diet (n = 20; 10% of energy from lipids) or a high-fat diet (n = 20; 50% of energy from lipids). After 10 weeks, mice were divided into 4 groups based on feed: standard chow (SC; n = 10), standard with 15% GBF (SB; n = 10), high-fat diet (HF; n = 10) and high-fat diet with 15% GBF (HFB; n = 10) for 4 weeks. HFB exhibited lower gains in body weight (-21%; p < 0.01) and in all fat pads (p < 0.01) compared with the HF group. SC, SB, and HFB showed smaller retroperitoneal white adipose tissue diameters (p < 0.001). SB and HFB-treated mice showed lower levels of leptin, IL-6, and TNF-α compared with the SC and HF groups (p < 0.01). In the GBF-fed groups, there was a reduction in the abundance of Firmicutes (SB: -22%; HFB: -23%) and an increase in Bacteroidetes (SB: +25%; HFB: +29%) compared with their counterparts. We demonstrated that GBF consumption attenuated inflammation and improved metabolic status, adipose tissue remodeling, and the gut microbiota profile of obese mice. Novelty: Green banana flour (GBF) consumption, rich in resistant starch, regulates body weight in mice fed high-fat diets. GBF consumption improves fat pad distribution in mice fed high-fat diets. GBF improves obesity-associated systemic inflammation and regulates gut microbiota profile in mice fed high-fat diets.

Gut microbiota dysbiosis in polycystic ovary syndrome: association with obesity - a preliminary report

The objective was to explore if and how the microbiota changed in polycystic ovary syndrome (PCOS) women compared with healthy women. Eight obese PCOS (PO group), 10 nonobese PCOS (PN group), and nine healthy normal weight women (control) (C group) were enrolled. Insulin (INS), testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (E2), and dehydroepiandrosterone (DHEA) were detected with radioimmunoassay. Antimullerian hormone (AMH), fasting glucose, and hemoglobin A1c (HbA1c) were determined by a chemiluminescence immunoassay, glucose oxidase method, and HPLC, respectively. Gut microbiota composition was evaluated by PCR. Alpha diversity was assessed using Chao1 and the Shannon index. PCOS women showed significantly higher T, LH, and LH/FSH and lower FSH levels than the C group (p < 0.05). The AMH level was significantly higher in the PO than in the PN group (p < 0.05). The PO group presented a significantly higher fasting INS level and HMOA-IR scores than the other groups, lower observed SVs and alpha diversity than the C group, higher beta diversity than the PN group (p < 0.05), and decreased abundances of genera (mainly butyrate producers). Regression analysis showed that decreased abundances of several genera were correlated with higher circulating T and impaired glucose metabolism. PCOS is associated with changes in the gut microbiota composition. Obesity has a driving role in the development of dysbiotic gut microbiota in PCOS.

Changes in Intestinal Microbiota of Type 2 Diabetes in Mice in Response to Dietary Supplementation With Instant Tea or Matcha

OBJECTIVE

Gut microbiota plays a key role in metabolism and health in diabetes patients with gastrointestinal microbiota dysbiosis. Thus, regulating the ecological balance of gut microbiota may provide a pathway toward improvement for these patients. Our previous study showed that functional ingredients in tea may inhibit cornstarch digestion in vitro.

METHODS

A cornstarch-tea diet was developed, and in this study we investigated the effects of such a diet on blood glucose and gut microbiota in diabetic mice.

RESULTS

Diabetes resulted in significant weight loss, hyperphagia and hyperglycemia. 16S rDNA sequencing revealed that in diabetes there is significantly increased Bacteroidaceae, Helicobacteraceae, Ruminococcaceae, Enterobacteriaceae, Rikenellaceae and Saccharibacteria_genera_incertae_sedis, and significantly decreased Lactobacillaceae, Prevotellaceae, Coriobacteriaceae, Verrucomicrobiaceae and Bifidobacteriaceae. The cornstarch‒tea diet resulted in a trend toward reduced blood glucose, with particularly increased levels of Coriobacteriaceae, Lactobacillaceae, Prevotellaceae and Bifidobacteriaceae, and decreased Bacteroidaceae, Ruminococcaceae, Helicobacteraceae and Enterobacteriaceae.

CONCLUSIONS

Instant tea and matcha supplementation had beneficial effects on regulation of blood glucose and gut microbiota, reversing the changes in microbiota caused by alloxan injection. The cornstarch‒tea regulation pathway is involved in bacterium group regulation rather than single-species regulation, which suggests that cornstarch combined with tea may be used as a functional food supplement for diabetes patients.

Pharmacologic and Nonpharmacologic Therapies for the Gut Microbiota in Type 2 Diabetes

The gut microbiota is an important regulator of host metabolism. Metagenome analyses have demonstrated that the gut microbiota differs between patients with type 2 diabetes and healthy subjects, and several studies have shown that impaired glucose metabolism is associated with decreased levels of butyrate-producing bacteria. Gut microbiota-produced metabolites, such as short-chain fatty acids, amino acid derivatives and secondary bile acids, participate in metabolic and immunologic processes and, hence, pose putative links between the gut microbiota and glucose homeostasis. Strategies to prevent and treat type 2 diabetes through manipulation of the gut microbiota are being developed. These include replacement of the gut microbiota by fecal transplantation, consumption of fibres to promote the function and growth of beneficial bacteria and treatment with probiotic bacterial strains. Furthermore, it has been shown that many drugs, including drugs used for treatment of diabetes, have major impacts on gut microbiota and, thereby, potentially on glucose metabolism. In particular, the commonly used drug metformin has been shown to influence the functional capacity of the gut microbiota, and recent evidence indicates that this may contribute to the antidiabetes effect of metformin.

Gut microbiota in Malawian infants in a nutritional supplementation trial

OBJECTIVES

To examine whether two forms of lipid-based nutrient supplements (LNS) or a micronutrient-fortified corn-soya blend were associated with development of the gut microbiota in Malawian infants, to assess the microbiota profiles at the age of 6 and 18 months and to follow the changes during the 12-month period.

METHODS

This was a substudy of a 4-arm randomised controlled trial conducted in rural Malawi. Infants at the age of 6 months were randomised to receive no supplement during the primary follow-up period (control), 54 g/day of micronutrient-fortified LNS with milk protein base (milk LNS), 54 g/day of micronutrient-fortified LNS with soya protein base (soya LNS), or 71 g/day of micronutrient-fortified corn-soya blend for 12 months. Stool samples were collected at baseline (6 months) and end of trial (18 months). The 16S rRNA gene was amplified and subjected to multiplex sequencing.

RESULTS

A total of 213 infants had paired microbiota data at 6 and 18 months of age. The Dirichlet-multinomial test showed no significant difference in microbiota profile between the four intervention groups at either age (each P > 0.10). Bifidobacterium longum was most abundant at both ages. Lactobacillus ruminis, Shigella and Salmonella were present. The abundance of Prevotella and Faecalibacterium increased with age (each P < 0.001), while Bifidobacteriaceae and Enterobacteriaceae exhibited significant decrease (each P < 0.001).

CONCLUSIONS

Nutritional supplementation by LNS or corn-soya blend for twelve months did not affect the gut microbiota profile in the rural Malawian context.

Antimicrobial use in swine production and its effect on the swine gut microbiota and antimicrobial resistance

Antimicrobials have been used in swine production at subtherapeutic levels since the early 1950s to increase feed efficiency and promote growth. In North America, a number of antimicrobials are available for use in swine. However, the continuous administration of subtherapeutic, low concentrations of antimicrobials to pigs also provides selective pressure for antimicrobial-resistant bacteria and resistance determinants. For this reason, subtherapeutic antimicrobial use in livestock remains a source of controversy and concern. The swine gut microbiota demonstrates a number of changes in response to antimicrobial administration depending on the dosage, duration of treatment, age of the pigs, and gut location that is sampled. Both culture-independent and -dependent studies have also shown that the swine gut microbiota contains a large number of antimicrobial resistance determinants even in the absence of antimicrobial exposure. Heavy metals, such as zinc and copper, which are often added at relatively high doses to swine feed, may also play a role in maintaining antimicrobial resistance and in the stability of the swine gut microbiota. This review focuses on the use of antimicrobials in swine production, with an emphasis on the North American regulatory context, and their effect on the swine gut microbiota and on antimicrobial resistance determinants in the gut microbiota.