Can toothpaste with 'good' bacteria prevent fillings?

Good oral hygiene is not only vital for healthy teeth and gums – it could help prevent serious disease, research now shows.This is due to the vital role played by the oral microbiome, the community of microorganisms that live in the mouth: an imbalance between ‘bad’ and ‘good’ bacteria is known to contribute to gum disease, tooth decay, bad breath and inflammation – and now it’s been linked to cardiovascular disease, depression, Alzheimer’s, diabetes and cancer.Research published last year in the journal JAMA Oncology found that ‘bad’ oral bacteria, including Porphyromonas gingivalis, were significant risk factors for pancreatic cancer – one of the deadliest forms of the disease.This was based on oral samples from 122,000 people, collected years before diagnosis, comparing the microbiomes of 445 people who developed pancreatic cancer with those who didn’t have the disease.One theory is that excessive ‘bad’ bacteria trigger chronic inflammation and alter immune responses, creating conditions that help cancer develop.But is standard brushing and flossing enough – or is there more we could do to maintain a healthy oral microbiome?There are now products that claim to target the oral microbiome. Are they worth the money?We asked James Goolnik, a dentist at Optimal Dental Health in London and an expert in the oral microbiome, to assess a selection. We then rated them. Research published last year in the journal JAMA Oncology found that ‘bad’ oral bacteria, including Porphyromonas gingivalis, were significant risk factors for pancreatic cancerHealthspan Oral Health Biotic£12.99 for 60 tablets, healthspan.co.ukCLAIM: Chewable tablets containing two clinically researched probiotics (live bacteria that boost levels of the ‘good’ type) to ‘support a healthy oral microbiome’. They also contain calcium and vitamin D to ‘maintain healthy teeth and gums’. Take one or two each night after brushing.EXPERT VERDICT: This is one of the more credible oral probiotic products because it contains Streptococcus salivarius K12 and M18 – both naturally live in the mouth and have been studied specifically in relation to reducing plaque and bad breath.This is better than marketing a gut probiotic for oral health as some other products do. But I couldn’t find independent studies confirming the stated two billion bacteria in one tablet remain viable throughout its shelf life. This is important as the bacteria need to be alive when you take them, not just when the product is manufactured.Taking them after brushing at night gives the bacteria longer contact with the mouth – possibly, although it’s not proved, as lower night-time saliva may improve colonisation. 7/10 Taking them after brushing at night gives the bacteria longer contact with the mouth – possibly, although it’s not proved, as lower night-time saliva may improve colonisationGutology Mineral Toothpaste£38.70 for three tubes, gutology.co.ukCLAIM: Contains added Lactobacillus plantarum HEAL19, a bacterium that ‘supports microbial balance’ and reduces inflammation. ‘No harsh ingredients that disrupt your oral microbiome.’EXPERT VERDICT: Some conventional toothpastes contain detergents that potentially damage microorganisms in your mouth. This is the first toothpaste to receive a ‘kind to biome’ certification [an independent, scientific quality standard].But that doesn’t mean it can actively rebalance an unhealthy oral microbiome – although the maker says it has a clinical trial planned to establish this.Lactobacillus plantarum HEAL19, is described as a ‘postbiotic’, meaning it supports the mouth’s existing bacteria rather than acting as a live probiotic. It also contains hydroxyapatite, a mineral thought to strengthen enamel. But human studies are still needed to confirm this – and other toothpastes also contain it.Like most of the products here, this is fluoride-free – not ideal for a toothpaste, but in this case there’s evidence hydroxyapatite performs comparably. But there’s more evidence for the decay-preventing effects of fluoride. 5/10 Like most of the products here, this is fluoride-free – not ideal for a toothpaste, but in this case there’s evidence hydroxyapatite performs comparablyInvivo Bio.me Oral Supplement £31.50 for 60g, freyaclinic.co.ukCLAIM: This fluoride-free powder contains eight strains of ‘beneficial’ Bifidobacterium and Lactobacillus which can ‘support the rebalancing of the delicate oral microbiome’, says the manufacturer. Mix 1g with water and use morning and night.EXPERT VERDICT: This contains eight bacterial strains – but more doesn’t necessarily mean better.There is some evidence for the individual strains leading to an improvement in bleeding gums, bad breath and imbalanced microbiome. But there’s no human trial proving this product selectively reduces harmful bacteria or that beneficial strains successfully colonise the mouth. Nor is there independent verification the organisms remain alive throughout the shelf life.However, a mouthwash is useful because swishing the powder around the mouth gives the live organisms direct contact with teeth, gums, the tongue and saliva. 3/10 There is some evidence for the individual strains leading to an improvement in bleeding gums, bad breath and imbalanced microbiomeBio Balance Toothpaste£23.88 for three, parlaoralcare.comCLAIM: This toothpaste contains ‘advanced technology’, to help ‘protect the natural balance of bacteria in your mouth’ and fluoride ‘to reinforce enamel against acid erosion and decay’. The bacteria have been heat-treated, which the company says makes them stable throughout the toothpaste’s shelf life.EXPERT VERDICT: The heat-treated Lactobacillus in this (known as a paraprobiotic) are bacteria that have been killed but their useful cell parts retained. Research suggests heat-treated Lactobacillus may help support the balance of key bacteria in the mouth.The company says tests show heat-treated Lactobacillus can increase beneficial bacteria, such as Corynebacterium, and reduce ‘bad’ bacteria, such as Fusobacterium and Prevotella, linked to gum disease.But while this has been shown for these bacteria, there is no evidence this is the case for the finished toothpaste. 6/10 The company says tests show heat-treated Lactobacillus can increase beneficial bacteria, such as CorynebacteriumLuv Biotics Dental Hygiene Lozenges£8.95 for 30 lozenges, hollandandbarrett.comCLAIM: Contains ‘clinically studied probiotic strains’ to maintain a thriving oral microbiome ‘and to ‘tackle the root cause of halitosis’. Chew up to three a day, between brushing, to help good bacteria get to parts of the mouth ‘where biofilms [sticky layers of microbes] form’.EXPERT VERDICT: These lozenges contain the probiotic strain Lactobacillus reuteri SGL01: a 2026 study found this could inhibit the growth and biofilm formation of Streptococcus mutans, a bacterium strongly associated with tooth decay.But this was a laboratory study. More research is needed to see if the product produces meaningful changes in oral health.A lozenge also dissolves slowly, allowing prolonged contact with saliva and gums.But this product doesn’t contain fluoride – and three a day would last just ten days, costing about £27 per month. Simply brushing properly twice a day with a standard fluoride toothpaste would also remove biofilms. 4/10 This product doesn’t contain fluoride – and three a day would last just ten days, costing about £27 per monthBiome Dental Sachets£34.99 for 28 sachets, thehealthbox.co.ukCLAIM: This is formulated ‘to support a healthy oral microbiome’. It contains four probiotics, plus a yeast. After night-time brushing and flossing, empty one sachet onto the tongue.EXPERT VERDICT: This is one of the stronger probiotic products because it contains four clearly identified live strains – Lactobacillus helveticus Rosell-52, Lactobacillus rhamnosus Rosell-11, Bifidobacterium longum Rosell-175 and Saccharomyces boulardii CNCM I-1079.These four have been found to successfully compete with harmful microbes, reduce inflammation and support microbial balance. And the advantage here is that the four-strain combination has been used in human clinical studies – this research, by the maker, has reported reductions in plaque and swollen and irritated gums compared with a placebo.But I would like to see larger independent trials looking at longer-term changes.The sachet format is sensible and convenient. But at £34.99 for a four-week supply, this product is expensive. 8/10