Chattering bacteria: quorum sensing

The more I study nutrition and gut health, the more I marvel at how cleverly we are designed, and how much we depend on the living world within us – or should I say the world living within us!

Quorum sensing

Inside our dog’s body is a bustling community of microbes. Trillions of them. They live mostly in the gut and, for the most part, they get along. But they aren’t silent passengers; they’re in constant communication. Bacteria talk to each other using chemical signals in a process called quorum sensing. It’s how they share information, take collective decisions and switch on behaviours – some of which can cause real problems.

Chatter

Essentially, quorum sensing is chatter between cells. I’m no molecular biologist, but this idea of bacterial information-sharing was so fascinating that I just had to dig a little deeper. I mean, bacteria that talk to each other, have their own language, understand ‘foreign’ languages and, having listened, can adapt their behaviour accordingly. And then the idea of interloper viruses working as spies, eavesdropping on their neighbours! Surely there’s a kid’s book there for someone to write!

But seriously…

I came across quorum sensing while looking into the damage done by antibiotics and how food can help to repair it. An understanding of what goes on under the bonnet gives us a better appreciation of why feeding a healthy gut isn’t just good for digestion and stools, but for so many other reasons – from calming inflammation to easing anxiety, and much more besides.

First, the clever stuff

Bacteria can talk with their own species and with other species: they’re multilingual. They produce signalling molecules and communicate with their own kind in a species-specific language, in private conversations that only they understand. Keeping it in the family, so to speak. And they use their understanding of ‘foreign’ languages to keep track of what’s happening with other species in the community: who’s there, in what numbers and (perhaps most importantly) who has the upper hand.

A bacterial cooperative

A single bacterium – or even a small group of bacteria – won’t have much impact on their own. But when family gathers and releases the same signal, in numbers that reach a critical mass threshold (hence the quorum), those bacteria are powerful enough to act effectively together and achieve what they couldn’t do alone. This is where they start to coordinate behaviours with others of their own species. It’s their way of syncing behaviour, coordinating strategy and surviving more effectively as a collective. And it’s successful. Bacteria work incredibly hard to keep their host alive: they digest food, produce vitamins, repel bad microbes and support the immune system.

At least, that’s what the ‘white hats’ do.

The bacterial battleground: white hats v black hats

Quorum sensing also works against the host. Bad bacteria (the ‘black hats’!) lie low until they hit quorum. They avoid detection, slip past immune surveillance and only start producing harmful substances once they know they have the numbers to overwhelm the host. This is how some pathogens establish chronic infections, form resilient biofilms and become hard to treat.

That said, quorum sensing shouldn’t be seen as inherently harmful. Many helpful microbes use it to support repair, enhance immune tolerance, maintain gut lining integrity – even to heal wounds. It’s a tool and like any tool, its effect depends on who’s using it and in what context.

This is where food becomes powerful. Food is our tool, because all of these bacteria are competing for the same nutrients to survive. By feeding a varied diet that is rich in fibre, prebiotics and probiotics, we can shape the gut environment and in turn influence which microbes thrive, how they interact and what kinds of messages dominate the microbial conversation.

Shifting the balance

A varied diet encourages a more diverse microbiome. And in the microbial world, diversity equals stability – because a rich and varied community creates an obstacle to domination by any one species. This supports healthier forms of quorum sensing like protection, resilience and immune support. It even extends to the skin microbiome – yes, there’s chatter on the epidermis as well.

Fibre from foods like oats, lentils, sweet potatoes and certain vegetables serves as food for beneficial gut bacteria. These bacteria ferment the fibre and, in doing so, multiply and strengthen their presence in the gut community.

Prebiotics and probiotics help stabilise the gut microbiota, supporting healthy bacterial populations that may be less likely to trigger problematic quorum-sensing behaviours – and more likely to promote balance and cooperation.

Fresh or gently cooked ingredients provide a broader range of nutrients, natural enzymes and moisture compared to heavily processed kibble. Studies have shown that dogs on fresh diets often have more diverse microbiomes; diversity which is strongly linked to healthier immune signalling and more balanced microbial behaviour. Helping the ‘white hats’ outnumber the ‘black hats’. So, when we talk about functional foods for dogs, we’re not just talking taste – or even nutrition in the traditional sense. This is about changing the chatter.

Emerging research

Increasing awareness of quorum sensing and how it works has opened a pathway to creating drugs that fight bacterial infections in a completely different way from the traditional antibiotics. Plant-derived polyphenols that can be found in foods like berries and apples have been shown to disrupt harmful bacterial communication systems, including quorum sensing. This dual effect, both nourishing allies and dampening the troublemakers, is also known as the duplibioticeffect[1].

And recent science suggests diet may do more than shift the balance of species. Foods that seem able to influence bacterial behaviour are being studied for their therapeutic effects. For example, scientists studying wounds found that when harmful bacterial chatter is interrupted, tissues can repair more effectively, and chronic infections are less likely to take hold[2]. Certain probiotics and their metabolic byproducts also appear able to block pathogen signalling, curbing harmful coordination while strengthening beneficial communication[3]. Other laboratory studies show that compounds such as curcumin can reduce quorum-sensing signals linked to toxin release and biofilm formation, without killing the bacteria themselves[4].

This research is still young, especially in dogs. But it adds to the bigger picture: what our dogs eat may influence not only which bacteria thrive, but also how they talk and act. A single voice doesn’t have the effect of a multitude of voices. But change the bacterial conversation – or control the bacterial crowd – and you can change a lot.

And while we might not be able to switch off the chatter ourselves, we can give the white hats the best chance to keep sending the right signals for whole‑body health by supporting a balanced gut community through diet.

*****

References:

[1] Rodríguez-Daza MC, Pulido-Mateos EC, Lupien-Meilleur J, Guyonnet D, Desjardins Y, Roy D. Polyphenol-Mediated Gut Microbiota Modulation: Toward Prebiotics and Further. Front Nutr. 2021 Jun 28;8:689456. doi: 10.3389/fnut.2021.689456. PMID: 34268328; PMCID: PMC8276758.
[2] Zielińska M, Pawłowska A, Orzeł A, Sulej L, Muzyka-Placzyńska K, Baran A, Filipecka-Tyczka D, Pawłowska P, Nowińska A, Bogusławska J, Scholz A. Wound Microbiota and Its Impact on Wound Healing. Int J Mol Sci. 2023 Dec 10;24(24):17318. doi: 10.3390/ijms242417318. PMID: 38139146; PMCID: PMC10743523.
[3] Salman MK, Abuqwider J, Mauriello G. Anti-Quorum Sensing Activity of Probiotics: The Mechanism and Role in Food and Gut Health. Microorganisms. 2023 Mar 20;11(3):793. doi: 10.3390/microorganisms11030793. PMID: 36985366; PMCID: PMC10056907.
[4] Shariati A, Noei M, Askarinia M, Khoshbayan A, Farahani A, Chegini Z. Inhibitory effect of natural compounds on quorum sensing system in Pseudomonas aeruginosa: a helpful promise for managing biofilm community. Front Pharmacol. 2024 Apr 2;15:1350391. doi: 10.3389/fphar.2024.1350391. PMID: 38628638; PMCID: PMC11019022.

Important Considerations:

  • Always consult your veterinarian before making any significant dietary changes, particularly where there are pre-existing health conditions or dietary restrictions.
  • If you are feeding commercial food, check the label for ingredients before giving more. Excessive intake of any foods can have adverse effects.
  • Ensure (where possible) that you use high-quality, organic products specifically formulated for pets (or better still, human grade ingredients) to avoid any potential adverse effects.
  • Introduce new foods gradually to avoid adverse effects such as gastrointestinal upset or diarrhoea.
  • I provide nutritional information purely as a helpful guide. Nutritional information on ingredients is obtained from the US Department of Agriculture’s FoodData Central site (https://fdc.nal.usda.gov/index.html) and any nutritional information provided in recipes is based on an online calculator: calories and other information will vary based on brands, ingredients and other factors.
  • Check nutrient levels and recommendations for your dog’s weight, age and activity. For example this nutritional guideline produced by FEDIAF.
  • I am not a professional canine nutritionist but supporting research is cited.
  • The recipes shared were created by me and tested in my kitchen – and tasted and approved by our doggy friends!