Why your grandmother’s diet protected your hormones — and what happened when we stopped eating it

One hundred years ago, the average Mexican woman drank pulque or sour atole several times a week. She ate tortillas made from nixtamalized masa every day. She cooked beans with epazote. In some regions, homemade jocoque. In others, pozol fermented under banana leaf.

Today, 30% of the average Mexican dietary energy comes from ultra-processed foods [Marrón-Ponce et al., 2022, Journal of Human Nutrition and Dietetics]. Latina women in the United States lose the microbial signature of Prevotella copri — an ancestral Mesoamerican marker — with each additional year of dietary acculturation [HCHS/SOL, Circulation, 2024].

For years, the public conversation has attributed this to "calories" and "sugar". Science from 2020-2025 is starting to tell a different story: what we lost was not only nutrients. We lost a microbial ecosystem that, without anyone planning it, was modulating our hormones.

What your grandmother had in her jícara

Let’s start with pulque, because the scientific surprise is enormous.

A shotgun metagenomics study published in Systematic and Applied Microbiology (Rocha-Arriaga et al., 2020) characterized the microbial diversity of pulque throughout its natural fermentation. The result: 2,855 bacterial OTUs and 1,494 distinct fungal species. To put this in context, a typical commercial yogurt contains between 30 and 50 species. Pulque has microbial diversity 50 to 100 times higher than any industrial fermented product.

The dominant strains include Lactobacillus sanfranciscensis, Lactobacillus pulque (recently described), Leuconostoc citreum, Saccharomyces cerevisiae, Acetobacter boissieri, and Zymomonas mobilis. Some of these were characterized only in the last five years. Their hormonal functionality remains, to a large extent, an open hypothesis.

Tepache is another interesting story. At 72 hours of fermentation, the microbial community is dominated by Lactobacillus, Leuconostoc, Acetobacter, Lactococcus, with the yeasts Saccharomyces, Zygosaccharomyces, Candida, Meyerozyma [Reyes-Sánchez et al., 2022]. What makes tepache distinctive is a late acetogenic phase: it produces acetic acid in significant concentrations. That acetate is not waste: it is a cross-feeding substrate for Faecalibacterium prausnitzii and Roseburia in your colon, two of the main butyrate producers.

Pozol, fermented under banana leaf in Yucatán and Tabasco, follows a two-phase bacterial succession: Lactococcus and Leuconostoc at the start, late Lactobacillus plantarum. Tejuino from Jalisco is similar but simpler, with a liquid fraction dominated by Lactobacillus and a solid fraction by Weissella. A study by Ávila-Reyes et al. (2022) performed in vitro colonic fermentation of the indigestible fraction of tejuino and showed significant production of butyrate and propionate in human fecal culture — the first direct functional evidence of tejuino as a substrate for SCFA-producing microbiota.

The enzyme that changes the game: β-glucosidase

Here comes a surprise the probiotic industry rarely mentions.

The estrobolome — the set of gut bacteria that metabolize estrogens through β-glucuronidase — is dominated by a few specific strains. Honda et al. (2024) screened 84 lactic acid bacteria strains and found that only one (Levilactobacillus brevis KABP052) and three from Lacticaseibacillus rhamnosus have β-glucuronidase activity relevant to estrogen metabolism.

Here is the uncomfortable part: Lactobacillus plantarum, the dominant lactobacillus in all LATAM ferments analyzed (pulque, tepache, pozol, tejuino, jocoque), does not have that activity.

That means Mexican ferments do not act primarily through the direct estrobolome pathway. Their hormonal effect must happen through another route. And that route is β-glucosidase.

β-glucosidase hydrolyzes glycosidic bonds in plant phytoestrogens. Soy isoflavones are well known, but the Mesoamerican diet was not rich in soy. It was rich in lignans from corn, black beans, chia, flaxseed, and nopal. These lignans are bound to sugars in their natural form and need to be released by microbial enzymes to become biologically active.

What LAB strains from LATAM ferments do, day after day in your gut, is release aglycones: daidzein, genistein, enterolactone, equol (the last one only in approximately 30% of women, depending on whether they have endogenous Slackia isoflavoniconvertens). These aglycones have greater affinity for estrogen receptor β than for α — ERβ is the one that predominates in bone, brain, and blood vessels, not in breast or endometrium. Its effect is selectively modulatory: it helps where lack of estrogen produces symptoms, and protects where excess estrogen is a risk.

Nixtamal: the epigenetic intervention no one called that

Nixtamalization is one of humanity’s most sophisticated culinary processes. Treating corn with lime (calcium hydroxide) is not only about calcium intake or niacin availability (that was already known). It does something else:

• It solubilizes pentosans from the grain’s cell wall.
• It releases ferulates that were esterified to arabinoxylans.
• It modifies starch structure: when the masa cools, the starch retrogrades into RS3, the type of resistant starch most fermentable by the colonic microbiome.

Nixtamalized corn contains 3 to 5 times more resistant starch than untreated corn [Félix-Sámano et al., 2025, International Journal of Food Science].

And what does your microbiome do with that resistant starch? It ferments it. And the final products are butyrate, propionate, and acetate — the three short-chain fatty acids (SCFAs) with documented systemic effects.

This is where the hormonal loop closes. Butyrate is an HDAC inhibitor (histone deacetylase). When it inhibits HDAC at the promoter of the ESR2 gene, it increases expression of the estrogen receptor β. Result: at the same circulating estradiol level, your tissues respond more. Your hormonal sensitivity increases without needing to increase hormone levels in blood.

Mechanistically, nixtamalization is an intervention in estrogen sensitivity through butyric epigenetics. Your great-grandmother did not know this. She did it for two thousand years because corn treated with lime nourished better.

The transition that broke the system

Marrón-Ponce et al. (2022) quantified what many families already sensed: 30% of current Mexican dietary energy comes from ultra-processed foods. The inverse association with dietary diversity was significant (-0.42, p < 0.001). Each serving of ultra-processed food displaces several servings of traditional foods with more fermentable fiber, more phytoestrogens, more live microbes.

The HCHS/SOL study (Circulation, 2024) measured dietary acculturation in Latinos in the United States. Finding: each additional year in the U.S. correlates with lower abundance of Prevotella copri — an ancestral Mesoamerican signature — and an increase in Western Bacteroides spp. It is a pattern associated with cardiovascular risk and, plausibly, altered estrogen metabolism.

No study has directly measured how this transition affects perimenopausal symptom severity in Mexican women. That gap is one of the holes Lua wants to document with longitudinal data.

What this means for a woman today

Three honest points, without prescription:

One. The traditional Mesoamerican diet — real nixtamal, whole beans, regular traditional ferments, nopal, seeds, quelites — was not a "diet for hormones". It was simply how people ate. But it coincided with a microbial ecosystem that probably buffered hormonal symptoms. Not by coincidence: through mechanisms that science is only beginning to document.

Two. Returning to that diet is not about recovering nostalgia. It is about restoring three concrete mechanisms: phytoestrogen aglycones through β-glucosidase, colonic butyrate from nixtamal resistant starch, and general microbial diversity through exposure to live ferments. Each one has a documented molecular mechanism.

Three. Not all women will respond the same way. Polymorphisms in COMT, MTHFR, UGT1A1, and the presence or absence of specific bacteria such as Slackia isoflavoniconvertens (equol producer) determine part of the response. Women with C-section birth, formula feeding, and childhood antibiotics have a different baseline microbiota — adult ferments partially repopulate it, but they do not always restore full diversity.

Lua Labs’ open hypothesis

Lua is adding three new variables to the food log:

1. Tag "Traditional LATAM ferment" differentiated from Western fermented foods.
2. Tag "Real nixtamal" vs industrial flour.
3. IDMD-ancestral score (Mesoamerican Dietary Diversity Index): score 0-10 combining consumption of 10 traditional foods detected in the food log over a 14-day window.

The falsifiable prediction: Mexican women aged 42-52 with IDMD-ancestral ≥6 will show a Greene Score 1.5-2 points lower than matched-controls with IDMD-ancestral ≤3, greater luteal regularity, and fewer night sweat events.

This is testable with Lua’s current cohort if we introduce the tags today. We are going to do it.

Closing

It is not nostalgia, it is biochemistry.

And we are not saying "go back to your grandmother’s diet and your hormones will fix themselves". We are saying something more precise: there are identifiable microbial and epigenetic mechanisms by which that diet worked. Documenting them matters because no one else is doing it from the LATAM context. European probiotic science does not capture the effect of pulque, tepache, pozol, or nixtamal because its samples do not include them.

If your question is "what do I do with this?", today’s honest answer is: observe what you ate as a girl, what you stopped eating, and what happened to your symptoms. That is the question Lua is built to answer with data. Not with marketing.

This article is based on the internal Lua Labs report "LATAM ferments and hormonal microbial diversity" (L1.4, 2026-05-18). The hypotheses will be validated with the Lua user cohort throughout 2026.