Oral microbiome sequencing after taking probiotics

Summary

Recently, a friend recommended BioGaia Prodentis to me. It is a DTC oral probiotic you can buy online that is supposedly good for oral health. I thought it would be interesting to do some sequencing to see what, if anything, it did to my oral microbiome. BioGaia Prodentis is available online for $20 or less for a month's supply BioGaia BioGaia has a fascinating story. They are a Swedish company, founded over 30 years ago, that exclusively sells probiotics DTC. They have developed multiple strains of Limosilactobacillus reuteri, mainly for gut and oral health. They apparently sell well! Their market cap is around $1B—impressive for a consumer biotech. Going in, I expected scant evidence for any real benefits to their probiotics, but the data (over 250 clinical studies) is much more complete than I expected. Most notably, their gut probiotic, Protectis, seems to have a significant effect on preventing Necrotizing Enterocolitis (NEC) in premature babies. According to their website: 5-10% of the smallest premature infants develop NEC, a potentially lethal disorder in which portions of the bowel undergo tissue death. In March 2025, the FDA granted Breakthrough Therapy Designation to IBP-9414, an L. reuteri probiotic developed by BioGaia spinout IBT. This is not specifically for the oral health product, but it's for sure more science than I expected to see going in. Prodentis BioGaia Prodentis contains two strains of L. reuteri: DSM 17938 and ATCC PTA 5289. The claimed benefits include fresher breath, healthier gums, and outcompeting harmful bacteria. Sequencing with Plasmidsaurus Many readers will be familiar with Plasmidsaurus. Founded in 2021, the team took a relatively simple idea: use massively multiplexed Oxford Nanopore (ONT) to offer complete plasmid sequencing with one day turnaround for $15, and scaled it. Plasmidsaurus quickly became part of biotech's core infrastructure, and spread like wildfire. It also inspired multiple copycats. Compared to Illumina, ONT is...