The effects of a set amount of regular maternal exercise during pregnancy on gut microbiota are diet-dependent in mice and do not cause significant diversity changes

Background Diet and exercise can affect the gut microbiota (GM); however, the effects of the same amount of exercise on gut microbiota changes in people on a low-fat diet (LFD) and high-fat diet (HFD) during pregnancy are unknown. Do different nutritional conditions respond equally to exercise intervention? This study aimed to investigate the effects of regular maternal exercise during pregnancy on the GM in mice fed different diets during pregnancy. Methods Six-week-old nulliparous female KunMing mice were fed either a HFD or LFD before and during pregnancy. Each group of mice were then randomly divided into two groups upon confirmation of pregnancy: sedentary (HFD or LFD; n = 4 and 5, respectively) and exercised (HFDex or LFDex, n = 5 and 6, respectively). Mice were sacrificed on day 19 of gestation and their colon contents were collected. We then performed 16S rDNA gene sequencing of the V3 and V4 regions of the GM. Results The pregnancy success rate was 60% for LFDex and 100% for HFDex. Both Chao1 and Simpson indices were not significantly different for either LFD vs. LFDex or HFD vs. HFDex. Desulfobacterota, Desulfovibrionia Desulfovibrionales, Desulfovibrionaceae, Desulfovibrio, Coriobacteriia, Coriobacteriales, and Eggerthellaceae were markedly decreased after exercise intervention in LFDex vs. LFD, whereas Actinobacteria, Bifidobacteriales, Bifidobacteriaceae, Bifidobacterium, and Bifidobacterium pseudolongum were significantly increased in LFDex vs. LFD. Furthermore, decreased Peptostreptococcales-Tissierellales and Peptostreptococcaceae and increased Bacteroides dorei were identified in the HFDex vs. HFD group. p_Desulfobacterota, c_Desulfovibrionia, o_Desulfovibrionales, f_Desulfovibrionaceae and g_Desulfovibrio were markedly decreased in the LFDex group vs. HFDex group. Conclusions Our data suggested that quantitative maternal exercise during pregnancy resulted in alterations in GM composition, but did not significantly change the diversity of the GM. These findings may have important implications when considering an individual’s overall diet when recommending exercise during pregnancy