Biofilms

Introduction

Biofilms are one more subject discussed lately because of the importance given to the microbiota. In biofilms, microorganisms grow in multicellular aggregates encased in a sort of matrix produced by themselves. This aggregation provides them protection and surviving strategies. The dental plaque is a typical biofilm.

“The Role of Bacterial Biofilm in Chronic Infections”

The author of this article, Dr.Thomas Bjarnsholt, tests that biofilm infections are a new category of chronic infection which affect millions of people in the developed world, in contrast to acute infections caused by pathogenic bacteria and which in the past have caused millions of deaths
Biofilms infections are caused by colonies of bacteria growing in encased protective coat generated from their own production of a matrix of polymeric material for they attach to surfaces producing the biofilm, and thanks to what they survive to drastic environment and attack from antibiotics.
Common bacterial infections were very serious before, people could die for any type of disease that today can be cure with antibiotics. On the other hand, since the development of antibiotics, there has been an increase in slow‐progressing infections.
These infections cannot be easily detected and contrasted from antibiotic therapy resulting in persistent infections.
The author defines environmental biofilms as “general ecosystems of aggregating bacteria that are present in their natural habitat with an essential function”. These can include bacterial aggregates that live as commensalism with the human body without causing disease or those found in the environment.
Dental plaque was the first location in the human body were biofilms were described. The initial stages are dominated by bacteria in different stages of cell division forming monolayers, the progressive cell division in these microcolonies brings to the production of multilayered biofilms.
The first bacteria to colonize this environment are Streptococci.
The human gut is the next environment after the oral cavity, where commensal multispecies biofilms form. A wide range of bacterial species exists in the human intestine, which interact symbiotically with the host.
The host immune system is stimulated by the microbiota while the binding of pathogenic bacteria to the epithelium is competitively inhibited.
If this healthy microbiota is destroyed by antibiotics, chemotherapy or a change in the diet, intestinal colonization by pathogenic bacteria or viruses will happen, and this will cause disease.
In general, bacteria have two life forms during growth and proliferation. In one form, the bacteria exist as single and independent cells, in the other form are organized into sessile aggregates, and this is the biofilm growth phenotype. Acute infections are caused by independent bacteria while chronic infection should be the consequences of the biofilm.

“Biofilms and Herbal Medicine”

For Dr. Peter D’Adamo the biofilm’s attachments are the result of lectin-like adhesions between the microbe and the gut, respiratory, urinary and reproductive tract. Since many of these lectins rely on sugars, and the most common sugars on cells membranes are those of the ABO blood types, microorganisms have a specificity based on blood groups in order to attack.
One of the approaches for controlling bacterial infection involves the interference with the ability of communication among bacteria. Many bacteria modify their genetic expression based on the environmental conditions.
Bacterial organelles, as pilum and flagella and fimbriae are the tools that bacteria utilize to get stick together.
Flagella are projections that protrude from their body allowing them of moving around.
Pilum connect bacteria together, allowing for the formation of colonies and the exchange of genetic information, and which results in resistance to antibiotics. Fimbriae are used by bacteria to adhere to one another. A genetic mechanism allows the switch between pili and fimbriae based on the environment conditions as previously mentioned.
Dr. D’Adamo observes that the actions of cranberry juice on urinary tract infections seems to be the result of the juice’s high concentration of the sugar mannose known to block the attachment of two classes of fimbriae and interrupting this way the communication among the bacteria.

He mention as an example of the level of cooperation during biofilm formation a phenomenon called quorum sensing. The first bacterial colonists send a variety of signaling molecules towards the receptors of other bacteria inducing them to alter their own genes. This allows them to adhere to the biofilm and to produce additional signaling molecules.
Biofilms are object of intense research in biomedicine and may provide explanations of why certain infections are so difficult to eradicate in some patients. Most attention is on the discover of substances that interfere with the signaling that are involved in quorum sensing.
In the rest of the article the doctor investigates the different signaling molecules, enzymes in the process and the effects on bacteria communication, and natural substance which can interfere with this mechanism.
“The two most common auto-inducers seen in bacteria are known as AHL (N-Acyl Homoserine Lactones) and Auto-inducer family (AI-2, AI-3)”.

“AHL are signaling molecules found in many gram-negative bacteria. Common gram-negative bacteria include H. pylori (ulcer causing bacteria), Salmonella (food poisoning), Neisseria gonorrhoeae (gonorrhea), Spirochetes (Lyme disease), Proteus and E. Coli (urinary tract infections)”. They are inactivated by an enzyme called lactonase.

It looks like that a major source of lactonase activity is via the PON1 gene, which codes for the enzyme paraoxonase. The main effect of this enzyme is to block the artery clogging effects of LDL cholesterol by enhancing the antioxidant functions of HDL.
“An additional link between chronic infectious states and cardiovascular disease”.
Several natural products, including quercetin, plant bioflavonoid, pomegranate juice, and NAC (n-acetyl cysteine) have been shown to increase paraoxonase activity, but it looks like that most of the studies have been done in tissue culture or on rats.
Dr. D’Adamo observes that “there is quite a bit of variation (polymorphisms) in the PON1 gene and it is doubtful that the animal quercetin studies are extendable to humans, as each species metabolizes quercetin somewhat differently”.

The second series of signaling molecules used in quorum sensing are the “auto-inducer” The auto-inducers work on both gram-negative and gram-positive bacteria. “Common gram-positive bacteria include Staphylococcus, Streptococcus, and Clostridium (botulism)”.
“Some evidence indicates that foods containing furocoumarins inhibit their signaling. Common furocoumarins in the diet include grapefruit juice and bergamot. Some species of seaweed are also being investigated for their ability to jam bacterial signaling”.

Biofilm and Stress

In this part the doctor underlines the connection between stress, neurotransmitters related and biofilms.
The stress hormone norepinephrine affects parts of the brain where attention and responding actions are controlled. Norepinephrine is synthesized from dopamine. The gene for dopamine has shown some association linkages with the gene that code for ABO groups.

Both epinephrine and norepinephrine are present throughout the gastrointestinal tract. It looks like that blood group O individuals with high level of stress may have more problems with infections due to overgrowth in the gut, especially true for type O individuals with the “Hunter” epigenotype.
Dr. D’Adamo has his own classification of genotypes based on biometric and metabolic calculations, blood type and secretor status, family history and more. There are 6 genotypes and the book that describes this epigenetic classification is called “Change Your Genetic Destin”.

Herbal medicine and biofilms

In this section of the article the doctor considers the different herbs and relation to biofilms, their action and/or interference. I am only mentioning some of these.

Seaweeds seem to possess a very strong ability to resist biofilm formation, probably-as he defines- “an evolutionary adaptation to the harsh demands of living at the interface of land and sea”.

Andrographis paniculata has been used since the ancient times from Aryuvedic medicine and others, the plant extract exhibits antityphoid and antifungal activities. Andrographis is also reported to possess hepato-protective, antibiotic, antimalarial, and anti-inflammatory properties.

The main active component of this herb was reported at the time of the article to inhibit the bacterial quorum sensing system. A successive study using variations of this component verified this observation.

Schisandra chinensis is an adaptogenic herb used in Traditional Chinese Medicine to improve the ability of the body to respond to stress. The major constituents in schisandra are lignans found in the seeds of the fruit. Modern Chinese research suggests these lignans have a protective effect on the liver and an immunomodulating effect.

Eleutherococcus senticosus is also known as Siberian ginseng. The applicable parts of Siberian ginseng are the root and leaf. The lignin constituents seem to have immunostimulatory effects. As an adaptogen, Siberian Ginseng is considered to possess stress-modulating effects.
Siberian ginseng and Schisandra chinensis both stimulate the expression of chemicals involved in the chemical defense against stress.
The conclusion under the doctor view is that stress seems to really impact biofilm formation, therefore is very important controlling noradrenaline levels in the gut.
This herbal approach works well with whatever anti-lectin therapy (diet, anti-adhesion supplements) he uses with his patients.

Thanks for reading

Mariarosaria M.

https://wordpress.com/alp/?aff=36804

Resources:

http://www.dadamo.com/science/the lectin connection/natural products-research/biofilm and herbal medicine. Reviewed and revised on May 2018