It is generally view to be low. I would be inclined to say slow. I came across this study today that found that for another microbiome dysfunction that the partner showed significant shifts.  If you have a partner, you may want to have them do a uBiome test occasionally.

To the Study…

Partners of patients with ulcerative colitis exhibit a biologically relevant dysbiosis in fecal microbial metacommunities. Jul, 2017

“Fecal samples were collected from eight ulcerative colitis (UC) patients and their healthy partners ….

Fecal microbial communities were more similar among UC patients than their healthy partners (P = 0.024). UC individuals had a lower relative abundance of bacteria belonging to the Firmicutes, especially Blautia, Clostridium, Coprococcus and Roseburia (P < 0.05). Microbiota dysbiosis was detected in UC patients and their healthy partners. Relevant genera included Akkermansiam, Bacteroides, Escherichia, Lactobacillales, Klebsiella and Parabacteroides.

“In 1994, an investigation of 10 couples showed that individuals with IBD symptoms before marriage influenced their partners, resulting in similar symptoms in couples[12]. However, these results mainly focused on clinical symptoms and did not involve the gut microbial community.”

“Although there was no direct evidence that gut microbiota could spread between IBD patients and normal individuals, the results of this study suggested that fecal microbiota likely influence each other during long-term cohabitation with UC patients. Remarkably, our results indicated that the fecal microbiota composition was more similar among UC patients than among healthy individuals (Figure ​(Figure1).1). These findings further demonstrated that the gut microbiota composition, and alterations to it, plays a crucial role in the occurrence of UC.”

“Gut dysbiosis is considered one of the factors inducing inflammation in chronic IBD; however, its role in the etiology of ulcerative colitis is controversial. There have been many studies on fecal microbiota in recent years. The present study used a very sensitive method to assess bacterial strains and compared the microbiota in patients with inflammatory bowel disease with that of their healthy partners. The study assessed some type of bacteria only found in patients with UC. These bacteria are difficult to detect using less sensitive methods.”