Alternative protein sources as a means for fighting food insecurity have become more prevalent in various initiatives. Nevertheless, there are only a few cases with actual microbial food and feed production on an industrial scale. The overall landscape is developing, but as there are very few functional plants, it is not clear whether the regulatory framework is robust enough to ensure product safety and whether the regulatory framework does not include any unnecessary hurdles for alternative food and feed to reach the market. In this paper, a content analysis was performed of various European Level documents referred to microbial biomass value chains, including the potential substrates of agro-industrial sources. The literature sources were gathered using a snow-balling approach and further analysis was done on a keyword basis screening the documents for corresponding paragraphs. Quantitative sorting was done by assessing the keyword count, document types, and timeline. As a result, regulatory gaps and hurdles for microbial biomass production from agro-industrial side streams were elucidated.