CRISPR Can Rewrite Your Genes. It Cannot Rewrite Your Breakfast.

Picture this scenario.

A patient receives a CRISPR based gene therapy. The edit works. The faulty gene is corrected. The therapy reaches the right cells. On paper, the problem in the code is fixed.

That evening, the patient goes home and eats the usual dinner. Chips, a sugary drink, not much else. Breakfast tomorrow looks the same. So does lunch.

Does the gene therapy still work?

The DNA sequence has changed, and it stays changed. But whether that correction leads to better health depends on something gene editing was never designed to handle. Does the cell have the raw materials to act on its new instructions?

This is the gap between having the right genetic code and having the right conditions to use it. The people who study this gap most closely are not doctors or geneticists. They are the engineers who run biopharmaceutical manufacturing plants.

If you have never heard of a CHO cell, you are not alone. But if you have taken a biologic drug, such as an antibody based treatment, there is a good chance it was made inside one. Chinese Hamster Ovary (CHO) cells are used across the biopharmaceutical industry to produce therapeutic proteins in large bioreactors.

Bioprocess engineers learned something important. A cell line can be engineered well and still produce a poor batch if the feeding is wrong. In standard fed batch culture, cells start on a lean medium and then receive timed nutrient feeds. Productivity drops once nutrients run low and waste products build up [1].

One study showed this clearly. Researchers tracked a CHO culture producing a monoclonal antibody. When the amino acid tyrosine ran low, the rate of protein production dropped sharply. The cells were healthy. The genetic machinery for making the protein was intact. But output fell. Once tyrosine was added back through a feed, output recovered [2].

The cells did not forget how to make the protein. They did not have what they needed to do it.

This is why feeding strategy is treated as its own discipline in biomanufacturing. It is not an afterthought after the genetic design is finished. It is a factor that determines whether the design produces anything at all.

The same logic applies to the human body.

A field called nutrigenomics studies how nutrients affect gene activity. The basic idea is simple. Nutrients are not only fuel. They act as signals that cells detect and respond to. These signals influence which genes turn on, which turn off, and how proteins get built.

Amino acids are a clear example. They are the building blocks of every protein in the body, including proteins made from a newly corrected gene. Nine amino acids are essential, meaning the body cannot make them and they must come from food. A recent review notes that amino acids do more than build tissue. They also act as signals that influence cell signaling and the epigenetic regulation of gene expression [3].

In plain terms, food does not just supply bricks for construction. It helps decide which blueprints get used in the first place.

This part often gets lost in discussions about gene editing. A corrected gene is, in a real sense, an accurate blueprint. But blueprints do not build themselves. The actual work of transcription, translation, folding, and repair runs on nutrition.

There is another side to this. It is not only about missing nutrients. It is also about what diets high in ultra processed food do to the body's internal environment.

A major review in Nature Reviews Gastroenterology and Hepatology looked at how ultra processed foods and food additives affect gut health. The authors found growing evidence linking diets high in these foods to inflammatory bowel disease, colorectal cancer, and irritable bowel syndrome. Some additives, including certain emulsifiers and sweeteners, were shown to affect the gut microbiome and gut barrier [4].

Animal studies support this. One study fed mice a diet built from ultra processed foods for 10 or 30 days. After 30 days, male mice showed reduced expression of genes that maintain the gut barrier and higher levels of an inflammatory marker. Female mice showed increased inflammatory gene expression in the gut and shifts in gut bacteria [5].

Go back to the bioreactor comparison. This is like running a production culture in a medium that is not just low in nutrients, but also contains byproducts that stress the cells. No amount of genetic optimization upstream fixes a hostile environment downstream.

None of this argues against gene therapy. CRISPR and related tools are among the most important developments in modern medicine. For many conditions, correcting the gene is the difference between a manageable life and a serious illness.

But it helps to be clear about what gene editing is and is not. It edits the instructions. It does not replace the materials, the energy, or the conditions those instructions depend on.

Biopharmaceutical engineers do not stop working once the genetic construct is finished. They spend just as much effort on the feed strategy, because a strong design in a starved system underperforms. Human cells run on the same logic. They carry out complex genetic programs every second, and what they can do with those programs depends on what they are given.

So the practical point is simple. Future medicine may include genetic corrections we cannot yet imagine. But what is on the plate will still matter. As our ability to fix the code improves, the quality of the feed becomes the variable still left for us to manage.

CRISPR can rewrite the code. The feed strategy is still up to us.

Author:

Thamizhinian Vasudevan

Research Scientist

Founder, Biosparklence.

References

1. Sigma Aldrich. CHO media and feeds for optimized production of therapeutic proteins. Cited 2026.

2. Wechselberger P, Sagmeister P, Herwig C. A control strategy to investigate the relationship between specific productivity and high mannose glycoforms in CHO cells. Appl Microbiol Biotechnol. 2016;100(15):6427-41.

3. Blachier F. Relevance and safe utilization of amino acids in supplements for human nutrition: lessons from clinical and preclinical studies. Nutrients. 2026;18(2):296.

4. Whelan K, Bancil AS, Lindsay JO, Chassaing B. Ultra-processed foods and food additives in gut health and disease. Nat Rev Gastroenterol Hepatol. 2024;21(6):406-27.

5. de Menezes C, Campolim CM, Triana A, Oliveira KM, Calixto LGS, Xavier FG, Saad MJA, Carneiro EM, Prada PO. Effects of ultra-processed diets on adiposity, gut barrier integrity, inflammation, and microbiota in male and female mice. Nutrients. 2025;17(19):3116.

Thanks to safeer Rifai, where I found the inspiration from, for this blog