Devil_May_Kare t1_ja295y4 wrote on February 26, 2023 at 8:17 AM

Lots of common bacteria can make lactase. If you don't break up and absorb the lactose before it reaches the bacteria in your large intestine, they'll consume it for energy and produce carbon dioxide gas in the process. Fermenting a little lactose makes a big volume of carbon dioxide, which pushes on your guts in painful and inconvenient ways.

DirtyProtest t1_ja2gbhj wrote on February 26, 2023 at 9:50 AM

Can this affect nlood alcohol levels?

Devil_May_Kare t1_ja2kggc wrote on February 26, 2023 at 10:46 AM

I don't think there's a significant effect. Just because there's fermentation happening doesn't mean a lot of alcohol is being produced. It's probably similar bacteria to the first population active in sauerkraut, which produce a lot of bubbling and a negligible amount of alcohol.

Also there isn't very much lactose in milk. Even if you ferment it with a yeast that turns it into alcohol fairly efficiently, milk won't pass 2.5% ABV, which is half the strength of beer.

figmentPez t1_ja3edp9 wrote on February 26, 2023 at 3:35 PM

There is a condition called Auto-Brewery Syndrome that can cause significant amounts of ethanol to be produced by gastrointestinal flora, but I'm not sure if it has any links to lactose intolerance.