You are 89 percent bacteria. Only 11 percent of the cells in and on your body are human. The rest is a vast, teeming microscopic universe of organisms that have been with you since the moment you passed through the birth canal and made first contact with your mother's fluids. That universe is called your microbiome, and how well it functions determines, to a degree that most people never fully reckon with, how healthy you are.
Seventy percent of your immune system lives in your digestive tract. Not near it. In it. Which means that the balance of good and bad bacteria in your gut is not a digestive issue. It is an immune issue, a neurological issue, a mood issue, and increasingly, according to current research, a factor in conditions ranging from autoimmune disease to depression to cancer. This is not fringe science. This is where the serious research is going.
The Basics
Probiotics are good bacteria. The word microbiome refers to the microscopic world of organisms living primarily in your small and large intestines. Intestinal flora means the same thing. CFU stands for colony forming units, which is a single bacterium with the capacity to divide and multiply into a colony. Strains are subtypes of bacterial species, each with different behaviors and effects. Pathogens are bad bacteria. Their job, as far as your body is concerned, is to destroy good bacteria, invade healthy cells, and proliferate when your defenses are down. The good bacteria's job is to hold territory, produce antimicrobial compounds, support the intestinal lining, and train your immune system to recognize and respond to threats.
When the good bacteria lose ground, because of a poor diet, chronic stress, environmental toxins, pesticide exposure, or antibiotic use, the pathogens gain it. That is when illness and disease find their opening.
How You Got Your Microbiome
When you were a fetus, your digestive system was essentially sterile. Birth changed that. Passing through your mother's birth canal exposed you to her bacteria for the first time, entering through your eyes, ears, nose, mouth, and skin. Her breast milk then continued that process, delivering both new strains of good bacteria and prebiotic material, the food those bacteria need to survive and multiply. The health of a mother's microbiome has a direct and measurable impact on the immune development of her child. This is one of the most important and underappreciated facts in human biology.
What Depletes Your Good Bacteria
The list is long and familiar. Antibiotic medications, which kill indiscriminately, taking good bacteria down along with the bad. A diet high in processed food, refined sugar, and animal products. Chronic stress. Alcohol. Pesticide residue in food and water. Environmental pollution. These factors do not just reduce the number of good bacteria temporarily. If a particular strain gets depleted enough, it may lose the ability to repopulate at all. That loss is not always recoverable without supplementation.
What a Good Probiotic Actually Does
A strong probiotic strain survives the journey from your mouth through the acidic environment of the stomach, through varying concentrations of bile salts, past digestive enzymes, all the way to the lower gastrointestinal tract where it actually sets up and goes to work. Most probiotic strains on the market cannot do this reliably. They are common, weak, or poorly manufactured, and the majority of their cells do not survive the trip.
What you want is a strain with documented survival capacity at low pH, proven ability to adhere to the intestinal mucus lining, and demonstrated antimicrobial activity against specific pathogens. The GLB18 strain, Lactobacillus plantarum, meets all of those criteria. It has been shown in laboratory conditions to survive at a pH as low as 2.4, adhere to the intestinal lining, and produce protein compounds that specifically target and destroy pathogens including E. coli, salmonella, and listeria, while leaving other good bacteria intact. That selectivity is not common. It is, from a biological engineering standpoint, remarkable.
On the CFU Myth
Ignore the number on the label. A supplement advertising 50 billion or 100 billion CFU is not necessarily superior to one with 1 billion. CFU count is a compensation strategy used when the strain itself is too weak to survive the gastrointestinal journey intact. The logic is that if you flood the system with enough cells, some percentage will make it. That is not efficacy. That is waste with good marketing. A robust strain at lower concentration, one that actually survives and colonizes, outperforms a fragile strain at any number. Size matters too. Larger bacterial cells are generally more effective fighters, and because they are larger, their CFU count will always look lower than smaller, weaker strains. The number tells you almost nothing useful.
Where These Probiotics Come From
The strains I recommend, GLB18 for digestive immunity and GLB3 for lung immunity, were originally developed and manufactured in Bulgaria, sourced from flowers grown in the mountains of Europe. They are extracted from plant material and cultured entirely in raw organic vegetable juice, including pea juice and carrot juice, with no dairy medium, no animal ingredients, no GMOs, and no pesticides. They are 100 percent vegan, gluten free, soy free, and allergen free by FDA standards. Because they are plant based, they do not require refrigeration. They exist in a stable suspended state and activate when they reach the warm, food-rich environment of your digestive tract.
I was introduced to the concept of probiotics by Fred Bisci, my mentor and one of the most genuinely knowledgeable people I have encountered in decades of working in health and wellness. Fred has been fully raw vegan for over fifty years, has completed two forty-day water fasts, and has maintained a nutritional practice for most of his life. When I was building Juice Press, he told me directly: if you are going to offer a juice cleanse, you need an accompanying probiotic. I had never seriously thought about probiotics before that conversation. I went looking for the best one I could find, and through a connection to the University of Sofia in Bulgaria, I found it.
These strains were later studied by researchers at Harvard Medical School. The published paper is available at glb44.org. Harvard has one of the most serious probiotic research programs in the world, and their findings on this particular subset of Lactobacillus plantarum are worth reading.
I no longer have a commercial interest in these products. I sold that interest when I left Juice Press in 2019. I recommend them because in fifteen plus years of direct experience, I have not found anything better.
Common Questions
Can I take this with antibiotics? Yes. Antibiotics kill good and bad bacteria indiscriminately. Taking a probiotic during and after antibiotic treatment helps restore the good flora and supports healthier bacterial regrowth in the aftermath.
Does it cause gas or bloating? No. Unlike many common probiotic strains, Lactobacillus plantarum has been shown to relieve bloating and irritable bowel symptoms rather than contribute to them.
Is it safe for children and elderly? Yes. These strains are recognized by the FDA as safe for all ages in any quantity. They have been used in consumer products including yogurt starter cultures for over sixty years.
How often should I take it? Daily, not just when sick or traveling. The factors that deplete good bacteria, stress, poor sleep, environmental exposure, dietary variation, are continuous. Daily supplementation keeps the good flora at a consistent functional level.
For the science, start here:
GLB18 Center for Applied Studies and Innovation, University of Sofia
GLB44 Paper, Andrew Onderdonk, Professor of Pathology, Harvard Medical School, glb44.org
All statements herein have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.