Systematic review assessing the effectiveness of dietary intervention on gut microbiota in adults with type 2 diabetes

Abstract

Aims/hypothesisDespite improved understanding of the pathophysiology of type 2 diabetes mellitus, explanations for individual variability in disease progression and response to treatment are incomplete. The gut microbiota has been linked to the pathophysiology of type 2 diabetes mellitus and may account for this variability. We conducted a systematic review to assess the effectiveness of dietary and physical activity/exercise interventions in modulating the gut microbiota and improving glucose control in adults with type 2 diabetes mellitus.MethodsA systematic search was conducted to identify studies reporting on the effect of dietary and physical activity/exercise interventions on the gut microbiota and glucose control in individuals with a confirmed diagnosis of type 2 diabetes mellitus. Study characteristics, methodological quality and details relating to interventions were captured using a data-extraction form. Meta-analyses were conducted where sufficient data were available, and other results were reported narratively.ResultsEight studies met the eligibility criteria of the systematic review. No studies were found that reported on the effects of physical activity/exercise on the gut microbiota and glucose control. However, studies reporting on dietary interventions showed that such interventions were associated with modifications to the composition and diversity of the gut microbiota. There was a statistically significant improvement in HbA1c (standardised mean difference [SMD] −2.31 mmol/mol [95% CI −2.76, −1.85] [0.21%; 95% CI −0.26, −0.16]; I2 = 0%, p < 0.01), but not in fasting blood glucose (SMD −0.25 mmol/l [95% CI −0.85, 0.35], I2 = 87%, p > 0.05), fasting insulin (SMD −1.82 pmol/l [95% CI −7.23, 3.60], I2 = 54%, p > 0.05) or HOMA-IR (SMD −0.15 [95% CI −0.63, 0.32], I2 = 69%, p > 0.05) when comparing dietary interventions with comparator groups. There were no significant changes in the relative abundance of bacteria in the genera Bifidobacterium (SMD 1.29% [95% CI −4.45, 7.03], I2 = 33%, p > 0.05), Roseburia (SMD −0.85% [95% CI −2.91, 1.21], I2 = 79%, p > 0.05) or Lactobacillus (SMD 0.04% [95% CI −0.01, 0.09], I2 = 0%, p > 0.05) when comparing dietary interventions with comparator groups. There were, however, other significant changes in the gut microbiota, including changes at various taxonomic levels, including phylum, family, genus and species, Firmicutes:Bacteroidetes ratios and changes in diversity matrices (α and β). Dietary intervention had minimal or no effect on inflammation, short-chain fatty acids or anthropometrics.Conclusions/interpretationDietary intervention was found to modulate the gut microbiota and improve glucose control in individuals with type 2 diabetes. Although the results of the included studies are encouraging, this review highlights the need for further well-conducted interventional studies to inform the clinical use of dietary interventions targeting the gut microbiota.Electronic supplementary materialThe online version of this article (10.1007/s00125-018-4632-0) contains...

Diet and Mental Health: Review of the Recent Updates on Molecular Mechanisms

“…Moreover, type, quality, and origin of food shape the gut microbiota profile and affect its composition and function [52]. Higher intake of fiber [53], pre-and probiotics [54] have been shown to modulate the gut microbiota. Healthy dietary patterns, such as the Mediterranean diets and other plant-rich diets, have been related to increased diversity of the microbiota [55].…”

Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity in patients with diabetes mellitus type 2 infected with Epstein-Barr virus

“…As the first known human carcinogenic virus it is associated with various malignancies, such as Hodgkin's lymphomas (HL), Burkitt's lymphomas (BL), nasopharyngeal cancer (NPC) and gastric cancer (GC) [9]. EBV may establish a persistent infection and reactivate periodically into the lytic cycle which has impact on the pathogenesis of EBV-associated tumours [10][11][12]. According to some researches, patients with diabetes mellitus type 2 are more susceptible to infections due to hyperglycaemia-induced virulence of various microorganisms [13].…”

Typical indigenous bacteria in the cecum of ddY mice fed a casein–beef tallow diet or whole‐egg diet

“…Gut microbiota dysbiosis can induce an innate immune response and chronic inflammation, leading to age‐related pathologies and unhealthy aging (Kim & Jazwinski, ; Rocks et al, ; Shibayama et al, ). These relationships between the gut microbiome and host health, particularly during lifestyle‐related diseases, are affected by dietary components, variations, and styles (Celibert et al, ; Houghton et al, ; Libbey et al, ; Menni et al, ; Shikano et al, ).…”