Breastmilk contains many prebiotics to support the growth of beneficial bacteria in the infant’s gut. It also contains bacteria that seed the infant’s gut. Previous research has shown that the bacteria in breast milk do indeed take hold and colonize the gut, and so it is imperative to infant microbiome development. An article published last week sought to discover if the breastmilk microbiome changes depending on mode of delivery, especially since we have seen that C-section infant’s have much different microbiomes than their vaginally delivered counterparts. The scientists published their results in the journal Microbiome.

The scientists tested the breastmilk of 39 Canadian women. Despite various backgrounds, each woman’s milk was dominated by Staphylococcus, Enterobacteriaceae, and Pseudomonas. Moreover, there were not major differences in the breast milk microbiomes between modes of delivery, showing that it is not effected by C-section of vaginal birth. In addition, the gender of the baby did not change the microbiome either. Interestingly, the microbiomes were very different between mothers, meaning that babies are being exposed to highly diverse bacteria from milk. In one case 80% of the bacteria were staphylococci, and in another case more than 50% was Pseudomonas.

There is little evidence that shows how differences in breast milk microbiomes are affecting children. That said, we know the microbiome is critical to immune system development, and therefore it reasons that these differences may be important. In any event, it is useful to see that mode of delivery itself is unlikely to change the breastmilk microbiome.

Cirrhosis is a disease of the liver in which healthy liver tissue is replaced with scar tissue, preventing the liver from properly functioning. Scientists at Virginia Commonwealth University found that changes in the microbiome of saliva were found in cirrhosis patients in comparison to individuals without the disease.

The scientists analyzed the bacterial contents of both stool samples and salivary samples from patients with varying degrees of cirrhosis as well as healthy controls. Previous studies had shown that cirrhosis patients had altered fecal microbiomes and in this study, they found that patients also had altered salivary microbiomes. 102 individuals with cirrhosis were studied including 43 of them who previously had hepatic encephalopathy (HE), a severe result of liver disease that results in confusion, coma, and can even lead to death.

Patients who previously had HE saw a decrease in bacteria in their saliva that were normally in the body and an increase in bacteria that were pathogenic, including Enterobacteriaceae and Enterococcaceae, Similar results were found in their stool samples. Of the 102 patients, 38 of them were hospitalized within 90 days of the study. Those 38 individuals had greater salivary dysbiosis than those who were not hospitalized.

They also looked at an additional 43 individuals without cirrhosis and 43 with cirrhosis and looked at the inflammatory profile in the saliva. They found that the cirrhosis patients had immune deficiencies that were similar to that in the gut.

This study showed that the salivary microbiome was similar to the fecal microbiome in patients with cirrhosis. This provides evidence that you may be able to use saliva to predict the disease severity of patients with the disease as well as providing a tool for testing treatment options for patients with the disease.