The gut microbiome in pregnancy has been associated with various maternal metabolic and hormonal markers involved in glucose metabolism. Maternal ketones are of particular interest due to the rise in popularity of low-carbohydrate diets. We assessed for differences in the composition of the gut microbiota in pregnant women with and without ketonuria at 16 weeks gestation. Fecal samples were obtained from 11 women with fasting ketonuria and 11 matched controls. The samples were analyzed to assess for differences in gut microbiota composition by 16S rRNA sequencing. Supervised hierarchical clustering analysis showed significantly different beta-diversity between women with and without ketonuria, but no difference in the alpha-diversity. Group comparisons and network analysis showed that ketonuria was associated with an increased abundance of the butyrate-producing genus Roseburia. The bacteria that contributed the most to the differences in the composition of the gut microbiota included Roseburia, Methanobrevibacter, Uncl. RF39, and Dialister in women with ketonuria and Eggerthella, Phascolarctobacterium, Butyricimonas, and Uncl. Coriobacteriaceae in women without ketonuria. This study found that the genus Roseburia is more abundant in the gut microbiota of pregnant women with ketonuria. Roseburia is a butyrate producing bacterium and may increase serum ketone levels.

BACKGROUND: Subclinical inflammation markers play a significant role in hyperemesis gravidarum (HEG). Simple hematological markers such as mean platelet volume (MPV), platelet distribution width (PDW), neutrophil-to-lymphocyte ratio (NLR), red cell distribution width (RDW), plateletcrit (PCT), and platelet-to-lymphocyte ratio (PLR) have been shown to reflect inflammatory burden and disease activity in several disorders. Ketonuria is a parameter used in the diagnosis of severe HEG, but its correlation with disease severity remains controversial. The relationship of subclinical inflammation markers with degree of ketonuria has not been examined previously. In this study, we aimed to determine the diagnostic value of these subclinical inflammation markers and the relationship between these markers and grade of ketonuria in patients with HEG.
METHODS: A total of 94 pregnant women with a diagnosis of HEG and 100 gestational age-matched healthy pregnant women were enrolled in this retrospective study. MPV, PDW, NLR, PLR, PCT, and ketonuria were calculated and analyzed from complete blood cell counts and total urine analyses.
RESULTS: Lymphocyte count was significantly higher in the control group (P < 0,001); NLR and PLR values were significantly higher in the HEG group (P < 0,001). Among inflammation markers, RDW increased significantly (P = 0,008) with an increase in ketonuria in patients with HEG. A statistically significant correlation was found between white blood cell (WBC) and NLR, PLR, PCT. A moderate uphill relationship was observed between NLR and WBC and a weak uphill linear relationship was observed between WBC and PLR and between WBC and PCT.
CONCLUSIONS: PLR and NLR can be considered effective markers to aid in the diagnosis of HEG. No marker was found to correlate with ketonuria grade except RDW, although the relationship of the severity of ketonuria with severity of disease is controversial. RDW increases as the degree of ketonuria increases.