Sentence:  Mostly, the microbiome is beneficial. It helps with digestion and enables <WSD>people</WSD> to extract a lot more calories from their food than would otherwise be possible. Research over the past few years, however, has implicated it in diseases from atherosclerosis to asthma to autism. 
Meaning of the word marked with <WSD> tags:  (Used as plural of '''''person'''''); a body of human beings considered generally or collectively; a group of two or more persons.