Distinct composition of gut microbiota during pregnancy in overweight and normal-weight women.
BACKGROUND
Results of experimental studies suggest that deviations in gut microbiota composition predispose to excessive energy storage and obesity. The mother influences the original inoculum and the development of infant microbiota, which in turn is associated with later weight gain.


OBJECTIVE
We characterized the gut microbiota in women according to their body mass index (BMI) and the effect of weight gain over pregnancy on the composition of microbiota before delivery.


METHODS
Overweight women (n = 18) were selected according to their prepregnancy BMI from a prospective follow-up study. Normal-weight women (n = 36) were selected as controls in consecutive order of recruitment. Excessive weight gain during pregnancy was defined as >16.0 kg for normal-weight and >11.5 kg for overweight states according to Institute of Medicine recommendations. The composition of gut microbiota was analyzed by fluorescent in situ hybridization coupled with flow cytometry (FCM-FISH) and by quantitative real-time polymerase chain reaction (qPCR).


RESULTS
Bacteroides and Staphylococcus were significantly higher in the overweight state than in normal-weight women as assessed by FCM-FISH and qPCR. Mother's weight and BMI before pregnancy correlated with higher concentrations of Bacteroides, Clostridium, and Staphylococcus. Microbial counts increased from the first to third trimester of pregnancy. High Bacteroides concentrations were associated with excessive weight gain over pregnancy (P = 0.014).


CONCLUSIONS
Gut microbiota composition and weight are linked, and mother's weight gain is affected by microbiota. Microbiota modification before and during pregnancy may offer new directions for preventive and therapeutic applications in reducing the risk of overweight and obesity.
Collado
Maria Carmen
MC
Functional Foods Forum and Department of Biochemistry and Food Chemistry, University of Turku, Turku, Finland. maria.collado@utu.fi
Isolauri
Erika
E
Laitinen
Kirsi
K
Salminen
Seppo
S
D000328:Adult; D001439:Bacteroides / Q000254:growth & development*; D001724:Birth Weight; D015992:Body Mass Index; D016022:Case-Control Studies; D003013:Clostridium / Q000254:growth & development; D015169:Colony Count, Microbial; D004734:Energy Metabolism / Q000502:physiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D005500:Follow-Up Studies; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D007231:Infant, Newborn; D050177:Overweight / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D011237:Predictive Value of Tests; D011247:Pregnancy; D011446:Prospective Studies; D012307:Risk Factors; D013210:Staphylococcus / Q000254:growth & development*; D013851:Thinness / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology*; D015430:Weight Gain