Probiotics: What You Need to Know for Better Patient Care

What Are Probiotics? 

Probiotics are live microorganisms, such as bacteria or yeasts from the gut or other microbiota that, when consumed in sufficient amounts, support health by targeting specific bodily functions. 

Health Benefits

Probiotics support gut health by enhancing the immune defenses of the intestinal lining and directly competing with harmful bacteria to maintain a balanced microbiome. They provide both immunological and non-immunological benefits.

• Immunological benefits include activating macrophages to enhance antigen presentation to B cells, increasing the production of secretory immunoglobulin A both locally and systemically, modulating cytokine profiles, and reducing immune responses to certain food antigens.
• Non-immunological benefits include aiding digestion, competing with pathogens for nutrients, lowering intestinal pH to create an unfavorable environment for harmful bacteria, producing bacteriocins to suppress pathogens, neutralizing superoxide radicals, stimulating mucin production to protect the gut lining, strengthening the intestinal barrier, competing with pathogens for adhesion sites, and modifying toxins released by harmful bacteria.

How Probiotics Work 

Probiotics exert their effects through multiple mechanisms:

• Antimicrobial Action: Lower intestinal pH, secrete antimicrobial peptides, prevent bacterial colonization, and block pathogen adhesion to epithelial cells.
• Gut Barrier Protection: Increase mucus production and strengthen mucosal integrity.
• Immunomodulation: Influence epithelial cells, dendritic cells, monocytes/macrophages, and lymphocytes.

Regulatory Status 

Probiotics are classified as nutritional supplements in the US and Europe, requiring only notification to regulatory bodies, such as the Spanish Agency for Food Safety and Nutrition. The Food and Agriculture Organization (FAO) and World Health Organization have established safety and efficacy guidelines for probiotic strains. 

The most frequently used probiotics belong to the Lactobacillus and Bifidobacterium genera. Saccharomyces cerevisiae is also used, whereas Escherichia coli and Bacillus strains are less common.

According to the FAO guidelines, probiotic products must specify:

• Genus, species, and strains
• Minimum viable microorganisms at the end of the shelf life
• Effective dose and expected health benefits
• Storage conditions

Key Characteristics of Probiotics

• Safety: Classified as Generally Recognized as Safe by the US Food and Drug Administration or Qualified Presumption of Safety by the European Food Safety Authority
• Survivability: Must withstand gastrointestinal conditions and reach the intestine alive to colonize
• Microbiota Interaction: Should function synergistically with the native gut flora
• Stability: Must maintain viability throughout the shelf life
• Efficacy: Must Contains sufficient microorganisms for clinical benefits, with strain-specific evidence (FAO recommends 10⁸-10¹⁰ CFU for colonic colonization)
• Protective Effects: Should inhibit pathogens and produce antimicrobial compounds
• Scientific Validation: Requires documented safety and efficacy
• Strain Quality: Must meet rigorous standards for potency and purity
• Storage Requirements: Optimal conditions must be specified
• Immune benefits: Should enhance host immune defense
• Labeling: Must disclose added components and comply with regulatory standards.

Probiotic Classification

Probiotics are identified using an alphanumeric nomenclature, indicating the genus, species, and strain, for example, Lactobacillus acidophilus CUL 60G, indicating the genus (Lactobacillus), species (acidophilus), and strain (CUL 60G).

A monostrain probiotic contains a single strain of species. A multistrain probiotic includes multiple strains of the same species and genus. A multispecies probiotic consists of strains from one or more genera.

Safety Profile

Probiotics have a strong safety record, with a low incidence of side effects in different populations, confirming their low pathogenicity. Adverse effects have been reported in only one case per 10 million consumers of the Lactobacillus strains.

This article is the result of an editorial collaboration between the Spanish Society of General and Family Physicians (SEMG) and Univadis Spain, a Medscape Network platform. 

This story was translated from Univadis Spain using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. 

Cortes holds a graduate degree in medicine and surgery and has completed multiple postgraduate studies. She earned a master's degree in nutrition from the University of Navarra in Pamplona, Spain, and a master's degree in nutrition from the University of Vigo, Spain. Additionally, she has a graduate degree in nutrition, a master's degree in management, and a master's degree in research from the University of Zaragoza in Zaragoza, Spain.