I had the good fortune of attending a webinar given by a friend and colleague yesterday on the topic of microbiomics and food. For those who are not aware, microbiomics is a fast growing field within the domain of micro and molecular biology that studies the entire population of micro-organisms associated with a particular habitat. A large segment of microbiomics researchers study the microbiomes associated with various human or animal organs (e.g. gut or skin) for reasons of improving human/animal health and/or nutrition. As an example some researchers in the field believe that understanding and modifying the human gut microbiome may be the key to weight loss/gain. Others think even larger human health impacts are possible, including prevention of or cures for cancer, diabetes, and almost every other chronic human or animal health condition. However, the field is expansive and microbiomes of other ecological niches are research areas of high interest and intensity at the moment, including those associated with various foods that humans eat.
The reasons for wanting to understand the food microbiome are many but one of the primary interests is in the area of food spoilage. Food spoilage results in a tremendous amount of food waste and also is a major source of many foodborne diseases. Many scientists, myself included, believe that spoilage potential and spoilage rates may be “predictable” if we had a thorough understanding of the associated microbiome and how it changes with time. One of the ways this is studied at the moment is with a technique known as the “spoiled pair.” It is a very simple concept and consists of analyzing the microbiome of a single food type in a spoiled example and one that is identical (same food, same age, same storage conditions) but has not spoiled. The two microbiomes are then compared in terms of total number of microbial species present and their relative ratios. I am simplifying here greatly as the comparisons may occur at any number of taxonomic/phylogenetic levels from kingdom to subspecies but most often either genus or species level comparisons are conducted, at least for bacteria. Bacteria are usually the main focus of these analyses as they are thought to be the primary drivers of food spoilage processes and their role in them is well understood in many cases. When these comparisons are done (and many have been in many different food types from a huge array of different sources) it is always (or almost always) the case that the spoiled member of the pair’s microbial population is much less diverse than the non spoiled member. In many cases the spoiled sample has been totally dominated by just a single or very few bacterial species where the unspoiled may have tens or hundreds of different species. What this means is unclear at the moment but I am suggesting that we look to the macrobiological level (planet wide) where we see a similar phenomenon. The areas of the planet that are the most “spoiled” (by this I mean are the most ecologically damaged) always or almost always have the lowest levels of macrobiological species diversity. It is a bit of a stretch I realize but it is quite interesting to think about.