The question the doctor could not answer
In 2025, a parent of mine finished a standard course of antibiotics. The infection cleared. The prescription ended. And then, nothing. No guidance on what came next. No product designed for what happens to the gut after the antibiotic course ends.
The weeks that followed were harder than the illness itself. Bloating that did not resolve. Loose motions that came and went. A gut that felt unsettled for far longer than it should have. When we returned to the doctor, the answer was what millions of Indians hear every year: this is normal, it will pass.
We tried what was available. Standard pharmacy probiotics, the sachets that every chemist stocks behind the counter. We took them faithfully. We felt essentially nothing. Not because the strains were wrong, but because the capsules dissolve in stomach acid before the bacteria ever reach the intestine. A delivery problem that almost no one talks about, and that the products themselves do not disclose.
520 million antibiotic courses are prescribed in India every year. Every single one ends the same way. The prescription stops, and the patient is left to manage the aftermath on their own.
What struck me was not the discomfort. It was the absence. There was no product in India designed specifically for post-antibiotic gut recovery. Not one. A category that should exist, that logically must exist given the scale of antibiotic use in this country, simply did not.
My background is in engineering and technology, not medicine. But engineers are trained to find where a system fails and build the thing that fills the gap. When I looked at post-antibiotic gut recovery, what I found was not a gap. It was a void.
Six months in the clinical literature
I spent the better part of six months reading. Primary literature, not wellness blogs. PubMed, not Instagram. What I found was a substantial body of clinical evidence on exactly this problem, evidence that had never been translated into a product designed specifically for the Indian consumer.
The first thing I learned was the scale of the damage. A 2011 paper by Dethlefsen and Relman in Science tracked the gut microbiome after standard antibiotic courses. The findings were sobering. Microbial diversity was significantly reduced. Some species did not return to baseline at six months. Symptom resolution was not the same as microbiome restoration. People could feel better while their gut was still substantially depleted.
The second thing I learned was that the evidence for recovery support was strong and specific. Not generic take-a-probiotic advice. Specific strains, at specific doses, in specific delivery formats, with specific timing. A 2017 Cochrane meta-analysis across 21 randomised controlled trials and 4,780 participants found that one particular strain, Saccharomyces boulardii, reduced the risk of antibiotic-associated diarrhoea by 53 percent. The World Gastroenterology Organisation 2023 Global Guidelines named it Grade A evidence.
The third thing I learned was why pharmacy probiotics do not work for most people. Standard gelatin capsules dissolve in stomach acid within minutes of ingestion. The probiotic bacteria never reach the small intestine. The clinical trials showing real outcomes consistently used one delivery format: delayed release capsules that pass through the stomach intact and open only at the higher pH of the intestine.
That combination, the right strains at the right doses in the right delivery format with the right timing, did not exist as a product in India. So I built it.
Why each ingredient was chosen
Every ingredient in Aegis Protocol has a specific clinical rationale. Nothing was chosen because it sounds good on a label. Everything is here because the evidence says it belongs.
The protocol is split across two capsules taken at different times of day. AM Shield is taken in the morning with breakfast. PM Rebuilder is taken in the evening before bed. That split is intentional. The gut needs different interventions during the day versus during sleep.
S. boulardii is a probiotic yeast, not a bacterium. This distinction matters because antibiotics cannot kill it. It survives the antibiotic course and can be started the day the prescription ends without being neutralised. In the post-antibiotic gut, it occupies intestinal binding sites that would otherwise be taken by less beneficial bacteria, produces enzymes that break down bacterial toxins, and modulates the inflammatory response in the gut lining. This is the ingredient with the strongest specific evidence for antibiotic-associated gut disruption of any probiotic compound in existence.
Goldenberg et al., Alimentary Pharmacology and Therapeutics, 2017. Cochrane-level meta-analysis: 21 RCTs, 4,780 participants, 53% reduction in antibiotic-associated diarrhoea risk. WGO 2023 Global Guidelines: Grade A evidence.
Antibiotics do not only disrupt the microbial population. They compromise the structural integrity of the gut lining itself. Zinc Carnosine addresses this through a mechanism that no probiotic strain can replicate. It stabilises the gastric mucosa, promotes epithelial cell migration and proliferation, and directly protects the gut lining from the permeability damage that underlies what many people describe as a leaky gut feeling after antibiotics. It works at the structural level, not the microbial level, which is why it belongs alongside probiotics rather than instead of them.
Mahmood et al., Gut, 2007 (PMID 16777920). RCT in healthy volunteers: Zinc Carnosine prevented NSAID-induced increase in intestinal permeability. In vitro: 3x increase in epithelial cell proliferation.
LGG is the most extensively studied probiotic strain in human clinical research. For post-antibiotic recovery specifically, it has demonstrated the ability to colonise the intestinal epithelium, produce antimicrobial compounds that inhibit pathogenic overgrowth, and support the structural integrity of the tight junction proteins that keep the gut lining sealed. The evening timing is deliberate. The gut is in its lowest-stress state during sleep, with reduced acid secretion and slower motility, which creates optimal conditions for bacterial colonisation.
Szajewska et al., Journal of Pediatric Gastroenterology, 2019. Systematic review confirming significant reduction in antibiotic-associated diarrhoea. WGO 2023 Global Guidelines: Grade A evidence.
Bifidobacterium species are among the most significantly depleted bacterial populations after an antibiotic course, and among the last to recover without intervention. B. lactis Bl-04 specifically supports the restoration of species richness in the gut, produces short-chain fatty acids that serve as fuel for colonocytes, and contributes to the overall diversity of the recovering microbiome. It is not a standalone solution. It works as part of the ecosystem being rebuilt alongside LGG and the other components of the PM capsule.
Leyer et al., Pediatrics, 2009. Randomised trial demonstrating significant reduction in antibiotic-associated GI symptoms. WGO 2023: recommended strain for microbiome diversity support post-antibiotic.
L-Glutamine is the primary fuel source for intestinal epithelial cells. During and after antibiotic treatment, the gut lining is under structural stress. The cells responsible for maintaining the mucosal barrier require adequate glutamine to repair and replicate. Without this substrate, the structural recovery of the gut lining is limited regardless of how many probiotic bacteria are present. L-Glutamine does not add to the microbial population. It provides the fuel that allows the gut lining itself to heal. This is a mechanism none of the probiotic strains cover.
Coeffier et al., Gut, 2010. L-Glutamine significantly reduced intestinal permeability markers in clinical subjects. Achamrah et al., Nutrients, 2017. Epithelial repair mechanisms confirmed in gut lining.
All five ingredients are encapsulated in HPMC delayed release capsules. The stomach operates at pH 1.5 to 3.5. Standard gelatin capsules dissolve within minutes, exposing probiotic bacteria to an environment they cannot survive. Studies of conventional probiotic capsules show 90% or more CFU attrition before the bacteria ever reach the intestine. The clinical trials on which the strain selection for Aegis Protocol is based consistently used delayed release delivery. The same strains in standard capsules would not produce the same outcomes. Delivery format is not a secondary consideration. It is the mechanism by which the protocol works.
The category that should have existed years ago
India is the world's largest consumer of antibiotics. 520 million courses per year from the private sector alone. Every one of those courses ends the same way. The prescription stops, and the patient is left to manage the aftermath with whatever they can find at a chemist's counter.
What is available at that counter is designed for general gut wellness, not post-antibiotic recovery. The strains are not always wrong. The doses are often too low. The delivery format means the bacteria frequently never reach the intestine. And nobody, not the pharmacist, not the doctor, not the product label, explains the 14-day window after finishing antibiotics when the gut is most receptive to recovery support and when the right intervention makes the greatest difference.
Aegis Protocol is not a wellness supplement. It is a recovery protocol. It has a defined duration of 14 days, a defined structure with AM and PM capsules each serving a specific biological purpose, a clinical basis drawn from the published literature, and a delivery mechanism that actually works.
We are building this because someone close to me needed it and it did not exist. We are building it in public, one article and one clinical reference at a time, because the more people understand what the evidence says about post-antibiotic recovery, the better the decisions they make after their next course of antibiotics. That is the company. That is the product. That is why we are here.
Chaitanya Reddy
Founder, Aegis Protocol Private Limited · Hyderabad, Telangana
Masters in Engineering Management, Northeastern University. Questions or clinical collaboration enquiries: support@aegisprotocol.in