Probiotics, explained with the receipts.

Oral probiotics

Strains like Streptococcus salivarius K12 and M18 colonize the mouth rather than the gut, and the research on bad breath, throat health, and the oral microbiome is young but growing fast. We cover which claims the evidence actually supports, how lozenges differ from capsules you swallow, and what to expect week by week.

Where we'd start: Oraticx Green Breath, a xylitol-sweetened mint lozenge with 8 billion CFU of the OraCMU strain, dissolved slowly in the mouth once a night after brushing.

Pet probiotics

Digestive trouble is one of the most common reasons dogs and cats see a vet, and probiotics are one of the few supplements with meaningful veterinary research behind them. We break down species-appropriate strains, when a probiotic is worth trying, and when the right answer is a vet visit instead.

Gut basics

Before comparing products, it helps to know what CFU counts really mean, why strain identity matters more than the species on the label, and why "more bacteria" is not the same as "better outcome". Our fundamentals guides give you the vocabulary to read any probiotic label critically.