Wikipedia
Serutan was an early fiber-type laxative product which was widely promoted on U.S. radio and television from the 1930s through the 1960s. It was manufactured by the J. B. Williams Co., which was founded in 1885 and bought out by Nabisco in 1971.
The origin of the brand name was straightforward. The makers merely decided to spell "natures" backwards, and "Read it backwards" was the product's advertising slogan. This was to differentiate it as being a "natural" product as opposed to laxative brands which stimulated the colon by chemical action.
The product was almost uniformly promoted on programs whose core audience was known to be considerably older than the typical television viewer. Serutan is especially associated with The Lawrence Welk Show and The Original Amateur Hour, both of which were also sponsored by J. B. Williams products Sominex, a sleeping pill and Geritol, a vitamin supplement. Serutan was the target of numerous jokes by Bob Hope and other radio comedians during the 1930s and 1940s.