The environment is full of potentially harmful microbes, but the probability of getting harmed is vanishingly small under normal circumstances. Harm requires a series of unlikely events to occur. Direct interaction, a portal of entry (transmission route), avoiding attack from host immune system, multiplying rapidly, extracting nutrients from host system, reaching target organ(s), etc.
In terms of food, our behaviour hugely reduces the probability of direct interaction with harmful bugs. There's a good reason why we instinctively toss out anything that looks, tastes or smells bad. Let's just call it "strong natural selection". Brewers are usually very selective when it comes to the quality of ingredients, but even when some potentially harmful microbes do get passed our innate quality control, they get destroyed by the established brewing process. After noting how rank spent grains get after a day in a waste bucket, I wouldn't ever opt for so-called "raw ale". Although, to be fair, the ethanol produced by yeast is going to keep most things in check, assuming they haven't been given sufficient time to establish and produce potentially harmful secondary metabolites, e.g., mycotoxins. A good reason to pitch enough healthy yeast, aye?
The report of a fatality due to consuming coconut milk infected by
Arthrinium saccharicola doesn't describe normal circumstances. The coconut was stored inappropriately for over a month and was most likely damaged to provide a portal of entry for the
A. saccharicola, which then established and produced a harmful mycotoxin.
I don't see any cause for real concern, especially for brewers.
