Biofilms and Disease: Why should I care?

Slime biofilm
The application of biofilm science to the study and control of chronic bacterial infections
William Costerton, Richard Veeh, Mark Shirtliff, Mark Pasmore, Christopher Post, Garth Ehrlich
Published in Volume 112, Issue 10
J Clin Invest. 2003; 112(10):1466–1477 doi:10.1172/JCI20365

Anyone who has felt plaque on their teeth, seen films at the edge of a pond, found  thick slimy glop when cleaning out a sink or fountain or suffered a respiratory infection has come into contact with biofilms.  When certain bacteria are in wet environments, they attach and send out signals to attract other bacteria called  “quorum sensing” molecules.  When the other bacteria start congregating, they start differentiating into bacteria that attach, that transport nutrients, that digest, that form protective films or crusts, adjust resistance and become far more formidable than any bacterium alone.  The biofilms are made of the bacteria, the water and the proteins, sugars and DNA that the bacteria exude.

efflux pumps
Source: The Antibiotic Paradox (Stuart B. Levy, M.D.)

For instance, when you get a respiratory virus, your bronchi are moist sites for bacterial complications.  When a bacteria lands, it calls others and makes a biofilm that blocks oxygen intake, causing you to cough. The biofilm protects the most interior bacteria. When you take antibiotics, the surface bacteria adapt by taking in samples of the antibiotics, “tasting” them with tiny efflux pumps and figuring out how to adapt.  They communicate this information to other bacteria in the biofilm.  This is how bacteria get resistant to the antibiotics.  They are even able to recombine with dead bacteria from other diseases to learn chemically how to protect themselves.  This is why our antibiotics have become less effective and why we have resistant “superbacteria”.

Bacteria take on different functions.

There are herbs that being weaker than antibiotics, sneak in under the radar of the bacteria and disable their efflux pumps, which is why you ought to take those herbs together with antibiotics.  This is a direct attack on bacterial resistance.  But new biosignal technology based on plant compounds called furanones disrupts the biofilm in different ways.

Biosignal technology prevents or disrupts resistant biofilms without killing bacteria.  Instead it blocks the quorum sensing molecules that allow the bacteria to congregate and other signaling molecules that affect virulence and resistance.  This approach to bacterial control is aimed at delivering treatment while sidestepping  bacterial resistance.

There is a red seaweed, Delisea pulchra, that is not colonized by bacterial films, unlike most.  This is used by the Australian firm Biosignals which has synthesized the chemicals and uses them for medical equipment and contact lenses.  The scientists found that the seaweed was rarely covered in bacterial biofilm colonies. They established that the seaweed uses natural chemicals, furanones, to keep it free of biofilms. The furanones jam cell-to-cell signaling systems that are pivotal to the ability of bacteria to form and maintain biofilms.

Delisea japonica may contain biofilm-inhibiting substances.

Preventing bacterial communication suggests that furanones may be effective against a wide range of bacteria.   In vitro studies have found that many furanones are useful against cholera, penumonia, cystic fibrosis-related infections, food poisoning,  golden staph infections and tuberculosis. Some of these bacteria have become resistant to current antibiotics.  Now, in vitro studies bathe the bacteria in a solution with the furanones, which is not the way your body works, so there isn’t direct oral administration evidence yet.  More research needs to be done.

Furanones are found in a variety of herbs.  Andrographis, for instance, and members of the parsley family.  There may be other seaweeds that have not been identified.  A colleague who is studying biofilms suggested putting vanillin into my fountain to stop the biofilm formation and it has probably slowed it down (as well as making the waiting room smell like vanilla.)

The class of furanones is large enough however that we should first look at the traditional uses of the plants, rather than looking first for constituents in the plants.  The traditional use has thousands of years of trial and error, while new drugs are unproven in the long term.

Not all biofilms are bad.  The probiotic bacteria that forms a living wallpaper along your gut, protecting you from disease, heavy metals and allergens, is one you want.  The appendix stores a biofilm of  probiotic bacteria in its cul de sac, to protect the body from potential pathogens in the GI tract that might wipe them out.  It allows us to be re-colonized by our symbionts.  We have good bacteria, most likely in thin films all over out bodies.

The appendix is a reservoir of microbiota. Source: NY Times Illustration by Bryan Christie Design

We evolved as clusters of bacteria, which differentiated into a superstructure housing lots of partially incorporated microorganisms like mitochondria and independent microorganisms like the lactobacilli in our gut.   We do need to be sure that strategies we use in preventing disease will not disrupt our own biological processes.

Lynn Margulis’ book,  Symbiotic Planet

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4 thoughts on “Biofilms and Disease: Why should I care?”

  1. Karen: Thanks for this explanation of biofilms. I will share it with my family. Found you through mutual friend Jim McDonald. I would love to know more research on biofilms.

  2. Karen:
    “The class of furanones is large enough however that we should first look at the traditional uses of the plants…” Can you provide any guidance on the traditional uses of the plants in this regard?

    -Rachel, Michigan

    1. Well all the plants are used differently. Andrographis is probably a good antibacterial herb because of the furanones, but the seaweeds aren’t used that way so those chemicals may be of benefit for living in their environment. In other words, we shouldn’t do constituent herbalism assuming similar uses just because of compounds in common.

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