Vegan in "thinks their sh*t doesn't stink" shocker
I think it's likely that people who eat a lot of vegetables have healthier gut bacteria than people who don't, a lot of them live off fibre, but it's more what they do eat than what they don't.
This was an interesting outcome from a poo transplant;
Colleen Kelly, a gastroenterologist at the Miriam Hospital in Providence, Rhode Island, has carried out around 200 faecal transplants for people with C. difficile infections. In 2010, she gave a transplant to a 32-year-old woman whose teenage daughter was the donor. The girl was borderline obese, says Kelly, but otherwise healthy. The transplant was a success and cleared up the woman’s C. difficile infection.
Around a year later the woman returned, complaining of massive weight gain. She had always been a normal weight, but had become obese despite diet and exercise regimes – even a medically supervised liquid protein diet. “She said she felt like there was a switch inside her body,” says Kelly. “No matter how much she ate or exercised, she couldn’t take the weight off. She’s still overweight now, and she’s very frustrated.”
It is the first recorded case of obesity apparently resulting from a faecal transplant (Open Forum Infectious Diseases, doi.org/zzr). Since it’s a one-off, Kelly says she can’t be sure of cause and effect. The antibiotics the woman also took could instead be to blame, says Martin Blaser, a microbiologist at New York University, who has found that these drugs can trigger obesity by wiping out “good bacteria”.
https://www.newscientist.com/article/mg22530083-600-not-just-obesity-faecal-transplants-weird-effects/