A recent study published in Nature (https://www.nature.com/articles/s41586-023-06838-3) identified specific bioactive components within a MDTF prototype (MDCF-2) that effectively promote the growth of beneficial gut bacteria in malnourished children compared to traditional therapeutic foods. This finding sheds light on the mechanisms behind MDTFs' effectiveness.
Program Reports:

The World Health Organization (WHO) and the Bill & Melinda Gates Foundation are currently supporting a large clinical trial of a MDTF called MDCF-2 (https://www.technologynetworks.com/immunology/news/therapeutic-food-repairs-malnourished-childrens-gut-microbiomes-382049). This trial, involving close to 6,500 children in Africa and Southeast Asia, aims to assess the long-term impact of MDTFs on child health.
Terminology:

It's true that there are different names used for MDTFs, which can be confusing. Here's a breakdown of the terms you mentioned:

MDF: Microbiome-Directed Food (general term)
MD-RUTF: Microbiome-Directed Ready-to-Use Therapeutic Food (specific type focusing on ready-to-use format)
MD-RUSF: Microbiome-Directed Ready-to-Use Supplementary Food (similar to MD-RUTF)
MDCF: Microbiome-Directed Complementary Food (specific type aiming to complement existing diets)
MDCF-2: A specific prototype of a MDTF currently being studied in clinical trials
Overall, the field of MDTFs is progressing rapidly, with promising research results and ongoing large-scale trials. While different names are used, they all generally refer to the same concept of harnessing food to positively influence the gut microbiome and improve health.