Short answer: Permanently
Specific answer: Depends on your medical condition and the advise from your health care professional, as no standardized recommendation exists.
The short answer assumes that you are in a generally accepted healthy state and not experiencing any adverse disease or gastrointestinal disease. The only difference between the two states when it comes to probiotics is the amount and specific strains that you would consume. If you are in a diseased state, then you will probably need specific strains of probiotics that may have a positive effect on your condition. This is were it is advisable to seek the advise from your health care professional.
If you are in a generally accepted healthy state, then probiotics should be consumed in sufficient amounts and on a continuous basis in order to confer their health benefits. Probiotics require their continual consumption in order to be fully realized.
The Importance of Probiotics to Health
The importance of probiotics to human health is evident in its accepted definition which is:
“live microorganisms that confer a health benefit on the host when administered in adequate amounts.” 1
The organ most heavily colonized with microbes is the gastrointestinal tract (GIT), which is host to over 500 bacterial species and is estimated to represent 70% of all the microbes in the human body. 2 The GIT has an estimated surface area of a tennis court (200 to 300 square meters). 3
The microbiota is not even throughout the GIT. Each section of the GIT contains different levels of microbiota, for example: 4
Large Intestine (Colon) 1011 to 1012
Figure 1. Spatial and temporal aspects of intestinal microbiota composition. A: variations in microbial numbers and composition across the length of the gastrointestinal tract. B: longitudinal variations in microbial composition in the intestine. C: temporal aspects of microbiota establishment and maintenance and factors influencing microbial composition. (Source: Gut Microbiota in Health and Disease)
Mechanisms of Probiotics
- alleviates digestive disorders such as constipation, diarrhea and IBS
- alters bacterial community structure to enhance evenness
- competitive adherence to the mucosa and epithelium
- competitive exclusion of pathogenic microorganisms
- concomitant inhibition of pathogen adhesion
- decreases pathogens and their toxins,
- downregulates gut inflammation
- helps to support healthy skin
- increases ability to digest food
- increases adhesion to intestinal mucosa
- increases ability to absorb calcium
- increases ability to assimilate nutrients from food
- increases ability to synthesize vitamin B
- increases ability to synthesize vitamin K
- inhibits attachment through stimulated mucin production
- interference with Quorum Sensing Signaling
- modification of the gut microbiota
- modulation of the immune system to convey an advantage to the host
- produces substrates that promote the growth of colonizing microbes (secreted exopolysaccharides, vitamins, fatty acids, sugars from undigested carbohydrates and others)
- production of anti-microorganism substances
- production of inhibitory compounds (bacteriocins, short chain fatty acids, and others)
- promotes immune responses against specific microbes
- reduces incidence of yeast infections, vaginitis and candidiasis
- reduces lactose intolerance
- stabilizes bacterial communities when perturbed (eg, with antibiotics)
- strengthening of the gut epithelial barrier
Figure 1. Mechanisms of action for probiotics in the gastrointestinal tract (Source: A Gastroenterologist’s Guide to Probiotics)
Table 1 provides a list of some of the processes and examples of the mechanisms of probiotics:
Table 1: Mechanisms of Probiotics
Mode Process Mechanism Examples
Barrier Function Decreased apoptosis of epithelial cells Decreased TNF-α production Lactobacillus rhamnosus GG
Increasing mucin production Increased expression of MUC 2 Lactobacillus sp
Host cell Antimicrobial Peptides Defensins (hBD protein) Increased up regulation of Defensin E coli strain DSM 17252S2
Cathelcidins By butyrate production Probiotic Antimicrobial Factors Lowering the luminal pH By secretion of SCFA’s Most of the probiotics bacteria
Bacteriocin production By Gram positive probiotics Microcin production By Gram negative probiotics Epithelial Adherence By competing with pathogens Directly or indirectly by producing protein that block adherence Immune Modulation Blocking pro Inflammatory molecules By attenuating IL-8 secretion or blocking the degradation of the counter-regulatory factor IκB Salmonella tyhimurium
Increasing mucosal immunity Increasing IgA Production L. casei
Interference with Quorum Sensing Signaling Blocks the communication between pathogenic bacteria By secreting molecules which blocks quorum sensing signaling L. acidophilus
Table 1: Various mechanisms of probiotics action on human intestine cells.
Abbreviations: TNF-α: Tumor necrosis factor alpha; MUC 2: Mucin 2, hBD: Hemoglobin subunit delta; SCFA: Short chain fatty acids; IL-8: Interleukin 8; and IκB: Inhibitor of kappa B. (Source: Probiotics: Mechanisms of Action and Clinical Applications)
Long-term Colonization of Probiotics
There is general agreement that probiotics do not establish intestinal colonization for long periods of time. 8 Most probiotics do not colonize the GIT and are no longer recoverable in the stool 1 to 4 weeks after stopping consumption. 9
As long as probiotics survive in the GIT, especially the harsh environment of the stomach, they can impact certain microbes which do colonize the GIT.
Probiotics can either become part of the human intestinal microflora or pass through the GIT and influence the existing microflora community. For example, Bifidobacterium longum becomes part of the human intestinal microflora, whereas Lactobacillus casei pass through the GIT and remodel or influence the existing microbial community. 10
In a study from 2011, investigators feed humans a fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. The evidence showed that the probiotic formula product did not change the gut’s overall bacterial composition, but instead altered gene expression patterns in the host’s resident gut microbes. These changes were transient, confined only to the time of the probiotic consumption.
Thus, if sustained benefit from a probiotic is desired, continued consumption is likely required. 11
Consuming probiotics in your diet should not be difficult. There are two methods to consuming probiotics, and when these two methods are combined, can provide adequate daily exposure.
The two methods are through:
- probiotic foods and drinks
- probiotic supplementation
Probiotic foods and drinks
There is a wide variety of foods and drinks that contain probiotics (usually fermented foods). These can be easily added to your diet on a daily basis by choosing one or two and switching to others to determine the best taste and effectiveness.
Foods that are fermented and contain probiotics For a more comprehensive list: List of fermented foods
Foods that are fermented and contain probiotics
For a more comprehensive list: List of fermented foods
Probiotics are also available as supplements. Some supplements contain one or two strains of probiotics that usually address a specific health issue. Other probiotic supplements contain a wide range of probiotic strains to be used on a daily basis for health maintenance.
Some of the widely known and available probiotic formulas that provide a selection of probiotic strains include the following brands. Note that this list is not comprehensive and complete and there may exist other brands that are just as good.
Modulating the Gut Microbiome – the Role of Probiotics and Prebiotics by Genova Diagnostics
Cover photo: raw sauerkraut