Determination of butyrates, a medicinal food to improve gut health-a chemical method using potassium triiodide.

The use of food as medicine is important in both treating and preventing illnesses. “Gut?-healthy foods” are thus essential as they help sustain our gut with a wide variety of beneficial bacteria. Short-chain fatty acids, e.g., butyrates, are a major class of metabolites produced by our gut microbiome. They play an important but incompletely understood role in many human diseases. Currently, methods like the HPLC and GCMS are most commonly used for the detection of butyrates. These methods, although popular, require specialized instruments and skilled professionals with specialized training to operate. The specialised instruments are also expensive to acquire and maintain. Therefore, there is a need for a cheaper and reliable detection method for butyrates. Hence, in this study, a protocol was developed using an enzymatic reaction coupled with a chemical and colourimetric method to detect and quantify butyrates in food samples. Briefly, the substrate acetylthiocholine was replaced in the Ellman method with butyrylcholine by esterifying the butyric acids found in food samples with choline chloride. Butyrylcholinesterase was then used for the hydrolysis of butyrylcholine. The product choline thus generated was then reacted with potassium triiodide to form choline periodide, a coloured complex that is measurable, spectroscopically. This novel potassium triiodide chemical method was found to be comparable in terms of accuracy when compared to the HPLC method. Results obtained from the quantification of butyrates found in <i>Cassia tora</i>, Kailan, Kangkong and Purple Kohlrabi Microgreen using this chemical method were within 87.23%, 91.44%, 97.49% and 97.73% respectively when compared to the HPLC method. Hence, findings from this study could lead to the development of a cheaper and more reliable method for the detection of food-derived butyrates, paving the way and contributing to the identification of food sources containing butyrates.