In about 85 percent of pregnancies, nausea, constipation, or vomiting occur, which can significantly disrupt a pregnant person's quality of life. In some cases, the problems are so severe, hospitalization is required. Researchers have now found that probiotics, or beneficial microbes, could help reduce those symptoms. The findings have been reported in the journal Nutrients.
Clinicians still aren't sure what causes those gastrointestinal issues durign pregnancy. "Various theories have been proposed, but none of them is conclusive," said lead study author Albert T. Liu, a professor of obstetrics and gynecology at the University of California Davis School of Medicine.
Probiotics can be taken as a supplements, but they are also present in fermented foods, which include kefir, kimchi, sauerkraut, yogurt, and tempeh. Different foods and probiotics can alter the gut microbiome, and they are thought to help maintain gut health by providing the body with a source of good microbes that can help us absorb nutrients and fight the bad microbes. But researchers are still learning about exactly what a healthy microbiome looks like.
There are many hormonal changes that occur during pregnancy, like increases in the levels of estrogen and progesterone. Those hormones impact the body in various ways, and have also been shown to affect the gut microbiome. These changes may lead to the gastrointestinal symptoms that are often experienced in pregnancy.
In this research, the scientists assessed the impact of probiotic supplements on 32 study participants, an unfortunately small sample considering the huge variation in the gut microbiome from one individual to another. Nevertheless, patterns were identified.
First, the volunteers took a probiotic supplement that contained mostly Lactobacillus bacteria twice a day for six days, then took two days off. Then they repeated the probiotic treatment. Throughout the study, the participants recorded their symptoms. This work indicated that when the probiotic was being ingested, nausea and vomiting were reduced. The amount of time spent being nauseous went down 16 percent, while for vomiting, the reduction was about 33 percent. Other symptoms, such as poor appetite, fatigue, and ability to maintain normal activities were also improved. Constipation was also reduced.
An analysis of fecal samples gave the researchers some insight into the bacterial species in the participants' microbiomes. The microbes Akkermansia and A. muciniphila were linked to more vomiting at the start of the study, and could act as biomarkers of those at risk.
A low level of bacteria that carry bile salt hydrolase, an enzyme that produces bile acid, was also connected to more vomiting in pregnancy. Probiotics can increase the levels of bacteria that produce bile acids. Vitamin E levels also increased, which was linked to less vomiting. These observations could explain the findings.
However, additional work will be needed to confirm the research, especially because of the small sample size.