SunGold Kiwifruit Supplementation of Individuals with Prediabetes Alters Gut Microbiota and Improves Vitamin C Status, Anthropometric and Clinical Markers

Abstract

Kiwifruit are a nutrient dense food and an excellent source of vitamin C. Supplementation of the diet with kiwifruit enhances plasma vitamin C status and epidemiological studies have shown an association between vitamin C status and reduced insulin resistance and improved blood glucose control. In vitro experiments suggest that eating kiwifruit might induce changes to microbiota composition and function; however, human studies to confirm these findings are lacking. The aim of this study was to investigate the effect of consuming two SunGold kiwifruit per day over 12 weeks on vitamin C status, clinical and anthropometric measures and faecal microbiota composition in people with prediabetes. This pilot intervention trial compared baseline measurements with those following the intervention. Participants completed a physical activity questionnaire and a three-day estimated food diary at baseline and on completion of the trial. Venous blood samples were collected at each study visit (baseline, 6, 12 weeks) for determination of glycaemic indices, plasma vitamin C concentrations, hormones, lipid profiles and high-sensitivity C-reactive protein. Participants provided a faecal sample at each study visit. DNA was extracted from the faecal samples and a region of the 16S ribosomal RNA gene was amplified and sequenced to determine faecal microbiota composition. When week 12 measures were compared to baseline, results showed a significant increase in plasma vitamin C (14 µmol/L, p < 0.001). There was a significant reduction in both diastolic (4 mmHg, p = 0.029) and systolic (6 mmHg, p = 0.003) blood pressure and a significant reduction in waist circumference (3.1 cm, p = 0.001) and waist-to-hip ratio (0.01, p = 0.032). Results also showed a decrease in HbA1c (1 mmol/mol, p = 0.005) and an increase in fasting glucose (0.1 mmol/L, p = 0.046), however, these changes were small and were not clinically significant. Analysis of faecal microbiota composition showed an increase in the relative abundance of as yet uncultivated and therefore uncharacterised members of the bacterial family Coriobacteriaceae. Novel bacteriological investigations of Coriobacteriaceae are required to explain their functional relationship to kiwifruit polysaccharides and polyphenols.

Nutritional Strategies in Prediabetes: A Scoping Review of Recent Evidence

“…Thirty of 52 studies (57.7%) that investigated changes in weight and/or BMI, reported significant improvement postintervention [ 17 , 22 , 24 , 26 , 27 , 29 , 31 , 32 , 33 , 40 , 43 , 58 , 59 , 61 , 65 , 71 , 74 , 77 , 84 , 87 , 88 , 90 , 93 , 98 , 99 , 101 , 102 , 109 , 110 , 111 ]. Similar proportions of statistically significant findings were observed for the waist and hip circumferences and/or waist-to-hip ratio (17/32 studies, 53.1%) [ 17 , 18 , 24 , 26 , 32 , 33 , 38 , 58 , 61 , 62 , 84 , 87 , 88 , 101 , 102 , 108 , 109 ] as well as systolic and diastolic blood pressure (16/31 studies, 51.6%) [ 17 , ...…”

“…The effect of plant-based foods, notably fruit and vegetables were reported by nine studies [ 17 , 18 , 25 , 33 , 82 , 95 , 96 , 100 , 108 ]. Berries, which include strawberries, blueberries and cranberries, were the most studied among plant-based interventions [ 95 , 96 , 100 ].…”

“…Kimchi [ 17 ], soybean leaf and banana extracts [ 18 ], curcumin [ 33 ], natto (Japanese fermented soybeans) and viscous vegetables [ 25 ], ultraviolet B (UVB)-treated mushrooms [ 82 ], and kiwi [ 108 ] were the subjects of one study each and showed overall positive outcomes in prediabetic patients. Glucose metabolism was only shown to be improved significantly in three studies [ 17 , 18 , 33 ].…”

“…Effects on insulin-related parameters were augmented in all plant-based interventions, except kiwi and UVB-treated mushrooms. Other metabolic risk factors such as BMI, blood pressure and lipid profile showed improvement at postintervention in kimchi, natto and viscous vegetables, kiwi and soybean leaf extract studies [ 17 , 18 , 25 , 108 ]. Curcumin was found to improve β-cells function and insulin resistance with few adverse effects [ 33 ].…”

Association Of Gut Microbiota During Early Pregnancy With Risk Of Incident Gestational Diabetes Mellitus: A Nested Case-Control Study

“…SCFA producing bacteria Bi dobacteriales and Coriobacteriaceae), and their abundance was under-represented in GDM cases in our study. We also found reduced abundance of Actinobacteria members in GDM women at genus level: Rothia, Actinomyces, Bi dobacterium, and Adlercreutzia, most of which were well known SCFA producing and anti-in ammatory microbial groups [15][16][17][18], and were previously found to be reduced in patients with type 2 diabetes mellitus [19,20] or GDM women in the second trimester [5]. Similarly, another study also reported an overall decrease of Actinobacteria in GDM cases compared with controls during early pregnancy, although with a very small sample size (n = 15) [21].…”