Nausea and vomiting affect about 85% of pregnant women. Pregnancy-associated nausea, constipation, stomach upset, bloating, fatigue, etc. have no apparent structural abnormality, so are referred to as functional gastrointestinal (GI) disorders.
Elevated oestrogen and progesterone during pregnancy change gut microbiome composition and function, which can significantly impact GI function. Yet whether probiotics are an option to reduce GI dysfunction and emotional distress has never been studied.
The current study therefore tested a hypothesis that probiotics may shift gut microbiota and metabolites to affect GI function during early pregnancy.
The team, from the University of California, USA, analysed whether probiotic supplementation influenced GI dysfunction and life quality within 24 hours through daily surveys and faecal analysis.
The study
The study involved 32 patients and the duration of the study was 16 days, consisting of two cycles of six daily probiotics and two days without probiotics. Participants entered the study without taking probiotics (Day 0) followed by taking probiotics (Probiotics 10, 2 capsules/day Nature’s Bounty, NY) for six days and off probiotics for two days. Then, the same cycle was repeated.
Each capsule contained inulin (200 mg) and 10 probiotics including L. plantarum 299v, L. bulgaricus Lb-87, L. paracasei DSM 13434, L. plantarum DSM 15312, L. salivarius Ls-33, L. brevis Lbr-35, L. acidophilus La-14, B. lactis Bl-04, L. paracasei Lpc-37, and L. casei Lc-11 (10 billion live cultures at the time of manufacture).
The participants were asked to enter a daily survey to understand whether probiotic intake influenced GI function within 24 hours. The survey questions included daily nausea and vomiting times as well as 17 questions that evaluated life quality. In addition, information regarding constipation and daily nausea hours was obtained for a subset of patients.
Faecal specimens were collected using an OMNIgene GUT kit. The preference was 1 specimen before taking probiotics, 2 without taking probiotics, and 3 while taking probiotics in the past 24 h - total of six specimens per participant.
Results
The resulting data suggested that probiotics significantly improved daily nausea and vomiting scores as well as overall life quality.
The team found that faecal biomarkers including vitamin E, A. muciniphila, and the copy number of bile salt hydrogenase gene (bsh, BSH) may predict the severity of vomiting. Furthermore, they found that probiotic intake increased the abundance of BSH-generating bacteria, which produced free bile acids thereby enhancing GI motility and metabolism leading to improved GI function.
High faecal α-tocopherol (vitamin E) levels were significantly associated with low vomiting scores suggesting its predictive value. Also, vitamin E levels, but not vitamin A levels, continuously rose with an increase in gestational age throughout pregnancy, which the authors say suggests the essentialness of vitamin E for pregnancy.
The abundance of Akkermansia and A. muciniphila was significantly associated with high vomiting times. Moreover, probiotic intake significantly reduced vomiting and the abundance of Akkermansia and A. muciniphila.
A. muciniphila are mucin-degrading organisms that use mucus as an energy source. Mucus levels need to be controlled but patients who do not have normal GI motility might have excessive mucus that requires increased A. muciniphila to digest it. Therefore, a high abundance of A. muciniphila can be a biomarker to predict vomiting in pregnancy.
Faecal bsh had a five to six-fold increase in response to probiotic intake. Additionally, high bsh levels were significantly associated with low daily vomiting scores and vomiting times. However, such a relationship was not noted for the baij encoding bile acid 7α-dehydroxylase that converts primary bile acids into secondary bile acids. In contrast, bsh encoded bile salt hydrolase deconjugates bile acids and is present in Lactobacillus and Bifidobacterium, which are routinely used as probiotics.
The authors say the function of bile acids in the enteric nervous system warrants further investigation. The report states: "Regulating bile acid signaling pathways may explain the benefits of probiotics in regulating GI function during early pregnancy.
"An additional study with an increased sample size is needed to confirm these exploratory findings. Other limitations of this study include not using a randomised trial and not blinding participants with a placebo. In addition, 24-hour effects of post probiotic intake were evaluated, assuming no carryover effect. Hence, long-term effects of probiotics were not assessed, which might lead to potentially underestimated probiotic effects."
Source: Nutrients
Liu, A.T.; Chen, S.; Jena, P.K.; Sheng, L.; Hu, Y.; Wan, Y.-J.Y.
"Probiotics Improve Gastrointestinal Function and Life Quality in Pregnancy"
https://doi.org/10.3390/nu13113931 (registering DOI)