Lysis sounds like complicated chemical jargon, but it shares an etymological origin with the everyday task of opening a jelly jar. Loosen and lysis both have the same ancient Indo-European root word that meant to break apart or divide. In the realm of pet food ingredients, hydrolysis involves using enzymes to break down meat from complex proteins into simpler amino acids and peptides. Those protein pieces tend to cause fewer allergic reactions in pets than untreated meat.
Hydrolysis boosted the palatability and digestibility of protein sources in cat food in a study published in the journal Pets. Hydrolysis may also promote species diversity in cats’ gut microbiomes.
“Overall, frozen and hydrolyzed were better for the cat’s health than meat meal, but they also have some potential risks…” South China Agricultural University researchers wrote in the journal. “Protein fermentation in the gut may produce toxic and harmful metabolites that pose potential health risks to the host. Hydrolyzed frozen meat can increase the diversity of the cat intestinal microbiome and may contribute to the intestinal health of the cat by significantly increasing the abundance of Actinobacteria to inhibit proteolytic activity.”
Compared to meat meal and untreated meat, hydrolyzed meat may reduce this potentially problematic protein fermentation in cats’ intestines.
Experiment using meat meal, meat and hydrolyzed meat in cat food
The researchers compared meat meal, frozen meat and hydrolyzed frozen meat in extruded diets fed to British Shorthair cats. The findings suggested that, along with improvements in palatability and nutrient digestibility, both frozen meat and hydrolyzed frozen meat offered positive impacts on immune markers and gut microbiota, relative to traditional meat meal.
The study involved 24 healthy adult British Shorthair cats. A four-day palatability trial was followed by a 45-day feeding study. Researchers monitored palatability, apparent digestibility, serum biochemical markers, immune responses, fecal microbiota and metabolomic profiles.
Cats preferred frozen meat and hydrolyzed frozen meat diets over the meat meal-based diet, with hydrolyzed frozen meat showing the strongest palatability. Improved digestibility of dry matter and crude protein was observed in both frozen meat and hydrolyzed frozen meat groups.
Fecal microbiota analyses revealed that cats fed hydrolyzed frozen meat had greater microbial diversity and higher abundances of beneficial bacteria such as Bifidobacterium. Conversely, the meat meal and frozen meat diets showed higher levels of proteolytic bacteria like Bacteroides and Alistipes. The researchers concluded that the hydrolysis process not only boosts protein digestibility but may also shift gut microbial composition toward a more beneficial profile.
Metabolomic analyses further supported this view, showing that hydrolyzed frozen meat altered tryptophan and bile acid metabolic pathways, with evidence pointing toward increased serotonin synthesis. This shift could potentially improve not only physical health but also mood and behavioral outcomes in cats, they wrote. While temporary soft stools were noted in the hydrolyzed frozen meat group, this effect resolved over time.
In the experiment, frozen meat and hydrolyzed frozen meat provided nutritional and physiological advantages over meat meal. As usual, the scientists added the caveat that additional research is needed to optimize hydrolysis protocols and evaluate long-term effects.