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My first pimple was a defining moment in my life. I recall feeling confused as to why something dreaded by teenagers was happening to me, a 9-year-old. That first pimple soon became my first breakout. From there, my skin never cleared up, despite spending a decade in and out of dermatology offices.
During one of those doctor appointments, I was given antibiotics for my acne. According to my dermatologist, the constellation of zits that marred my face was likely an overgrowth of the bacterium Cutibacterium acne. It’s well known that C. acnes play a key role in acne, so antibiotics to fight the bacterium seemed like the logical solution. We started with topical creams, which helped at first. Once those stopped working, potent oral antibiotics followed. No matter the treatment, the outcome was always the same: temporary improvement, only for the pimples to return with a vengeance.
By my mid-20s, it was clear that the acne was more than a lingering symptom of puberty; it was a chronic condition. I was facing the harsh reality that modern skin care may never give me a clear complexion.
That was also the time when I started my Ph.D. in food microbiology and was developing a deeper appreciation of bacterial systems. Naturally, I turned to examining my acne—and its refusal to leave my face—through the lens of a microbiologist. As it turns out, people blessed with healthy skin have comparable amounts of the bacteria C. acnes to those with acne. The devil’s in the details when we examine strain-level differences: acne-prone individuals tend to have a greater diversity of C. acnes strains—and that diversity includes more pathogenic strains.
Much to my chagrin, I learned there is a link between antibiotic resistance and pathogenicity, meaning that the C. acnes strains that are antibiotic-resistant are the same strains causing aggressive breakouts. This explains why antibiotics failed me time and time again: They selected for the resistant and hypervirulent strains of C. acnes. While they could briefly quell the bacterium on my face, the resistant strains just ended up taking over.
As a zit-faced grad student, I started a new research project that used lactic acid bacteria, or LAB, as a method for food safety. Basically, the idea was to explore how LAB could be used to colonize a food environment in order to prevent the outgrowth of spoilage or pathogenic bacteria. This is what’s known as a “protective culture”: we collaborate with good microbes in order to keep bad microbes—and foodborne illness—away. It’s the microbial approach to “the enemy of my enemy is my friend”; a strategic alliance that acknowledges not all bacteria are bad. Sometimes, we just want to create an environment with our preferred microbial population.
Spending long hours reading research on LAB amid a particularly disheartening breakout, I became fixated on the idea that the key to clearer skin lay in the strategic inclusion of beneficial bacteria through probiotics rather than the indiscriminate eradication of bacteria through broad-spectrum antibiotics.
Assuming a bloom of virulent C. acnes was to blame, I hypothesized that recolonizing my skin microbiota with probiotic LAB could effectively treat my acne.
It’s worth mentioning that LAB is an umbrella term for a group of bacteria that share certain characteristics, with the most notable being their ability to produce lactic acid. While not all LAB are classified as probiotics, LAB are the most commonly used probiotics in food products. In fact, yogurt, one of the most well-known probiotic foods, is a product of the LAB Streptococcus thermophilus and Lactobacillus bulgaricus, which convert lactose (the sugar in milk) into lactic acid.
Given yogurt’s well-established ties to gut health, I wondered if its probiotic effect was transferable to my skin microbiome. Interestingly, in 1912, a scientist named Dr. J. Peyri documented Lactobacillus bulgaricus as the first topical probiotic studied for skin diseases in a paper titled “Topical Bacteriotherapy of the Skin.”
So, channeling Peyri, I embarked on a borderline socially unacceptable experiment where I smeared yogurt on my face in the name of science.
My approach was simple: I applied plain yogurt on my face twice a day for roughly a month. I stuck with plain yogurt, avoiding flavored products containing added sugars, due to the potential link between high-glycemic diets and acne. While I wasn’t particular about brands, my main criterion was that the label indicated “live cultures,” which means that each gram contained at least 10 million LAB cells.
The results were outstanding. For the first time since childhood, I was acne-free.
I felt like I won the Nobel Prize for pimple science. Excited to share my findings with my sister-in-law, a fellow woman in STEM, I anticipated an enthusiastic discussion about microbiome science. Not wanting to burst my bubble, she gently informed me that yogurt face masks have been a natural remedy in India for generations. It turns out that what I saw as a microbiology breakthrough was just common sense in Ayurvedic practice.
In fact, countless sources praise yogurt for its skin care benefits, citing everything from lactic acid’s gentle exfoliation effects to its probiotic properties. Studies support these claims, showing that probiotics like Lactobacillus can help with acne by producing antibacterial compounds that inhibit C. acnes and by reducing inflammation. A clinical study out of Srinakharinwirot University’s Medical School found that a probiotic lotion derived from Lactobacillus decreased both the abundance of C. acnes and inflammatory lesions in patients with mild to moderate acne, with effects lasting up to four weeks.
In other words, I wasn’t reinventing the wheel; I was simply adding to the existing body of evidence. Ironically, years of dermatology visits and pricey serums hadn’t managed what a $3 tub of yogurt did in weeks.
Much like my first pimple was a defining moment in my childhood, my 20s were split into two eras: what I now call pre-yogurt face and post-yogurt face. Years later, I still apply yogurt to my face—though now, in maintenance mode, I do it just once or twice a week instead of twice a day.
With my acne finally under control, my focus has shifted. Now in my 30s, I’m increasingly intrigued by the potential anti-aging effects of probiotics on skin health.
Since starting this journey, I’ve earned my Ph.D. in food microbiology, and this experiment has played a pivotal role in shaping the scientist I am today. It ignited my interest in two emerging fields that are defining the future of medical science: food as medicine and microbiome therapeutics.
Both fields are emerging outside the traditional biopharma mold. Their intersection—where science meets people and where medicine meets food—is where I’ve found my calling.
What began as a lesson in food microbiology ultimately freed me from the inflamed, pus-filled hell I had lived with for so long—and it continues to fuel my curiosity about how we can harness microbes to improve health.
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